I did find it weird that with ST, the resistance still seems to be on a shoestring budget when they are the guys in power.
No they're not. Leia was drummed out of the New Republic Senate when her true parentage was revealed and her attempts to warn about the First Order dismissed as a fear-mongering power-grab, in the vein of her
real father. Those who believed in her left to support her, or still quietly supported her from within the government, but the Resistance was definitely hurting for stable resources. They were flying fifteen-year-old military surplus, or older. They had second-hand gear that they set up in an abandoned Clone Wars-vintage installation. And that was all after they'd had a couple years to get some momentum.
As for the larger discussion of aesthetics and technical and technological level on display. The difference between the PT and OT is not like the difference between Vietnam and Desert Storm. The GFFA isn't quite in technological stasis, but the rate of advancement has very much plateaued. They have had interstellar travel for tens of thousands of years. They've had some form of galactic government for much of that time. There
has been slow progress, but it's much more incremental than the great technological leaps we've known between the '60s and '90s. More like the rate of advancement between 2010 and now.
At the same time, while the Republic, and, after the Empire, the companies that still hewed to a Republic-era design ethic, was about making the best equipment they could, the Empire sacrificed quality for volume. Not saying the stuff produced was garbage -- far from it -- but the emphasis was less on precision engineering and more on what could be done to get as many out the door as fast as possible. Flat panels on the basic starfighters, instead of the more time- and resource-intensive (but more effective) angled versions. Interchangeable parts between helmets and ships, rather than dedicated components. In the real world, it's why we got the F-22 instead of the measurably, demonstrably superior F-23. The former used more existing, off-the-shelf parts.
And evolution isn't always improvement. Ford stopped making the Falcon in the US back in the '60s, but Ford Australia kept making it all the way through, with new design generations and upgrades and such. Most famously, the one that was used as Max's V8 interceptor. Soem years back, now, Ford US wanted to bring the marque back, but couldn't because Pep-Boys had bought the rights after Ford had let their claim lapse. So Ford brought the Falcon back to the US instead as the "500". Which was... mediocre, at best. Definitely a far cry from what the Falcon had been, and even still was over in Australia at the time. They also had rise and fall and rise and fall and rise and fall with the Mustang.
Messerschmitt lovingly crafted the 262 to incredible tolerances. Meanwhile, Supermarine cranked out the Spitfire as fast as they could. There's your Naboo N-1 to TIE Fighter comparison. The P-51 is a good analogue for the evolution of the Y-Wing. The early models were underpowered and had marginal range for what they would become -- and that's
before postwar models continued to be uprated through the 1960s. They were flying combat missions for a quarter of a century -- which in GFFA terms, is, like, three times that. And the F-15 has always been the go-to comparison for the Z-95/X-Wing, for much the same reasons. Equipment has been removed as unnecessary, components have been upgraded and reduced the amount of visible cockpit clutter. Advanced components were "downgraded" to more robust units that did the same thing.
As for missiles and tracking and such, we only ever see the surface in the films. We scratch a little below that in the shows. The EU and new ancillary material does
some technical noodling, but one thing that hasn't been emphasized is something that's an ongoing contest in the real-world, in the GFFA, in the Star Trek universe, etc.: Countermeasures are developed to thwart sensors and tracking; improved sensors are developed to beat the countermeasures; improved countermeasures are developed to defeat the improved sensors; back and forth for as long as there is more than one side to a struggle. At the start of the conflict, planetary defense forces had what they'd needed to deal with pirates and smugglers. The Separatists and their combat-purposed hardware necessitated improvement in defensive systems. So the CIS developed better battle droids and fighters and tanks and missiles to defeat what the Republic came up with. And so on. Gravity-well projectors, cloaking devices, droid-brain-guided missiles, ion cannons...
In Star Wars, Tarkin so utterly dismissed the smattering of
starfighters -- of all things -- sent against his 160-km-diameter battle station that he didn't even bother to raise main shields. The Rebel ships wallowed a bit going through the station's magnetic field, but we know what would have happened had actual shields been up. It's what they broke off to avoid at Endor (and one fighter didn't quite make it, per the script and novelization), and what we saw happen over Scarif. The shields over the reactor-exhaust heat-dispersion vents were just part of the running status of the station -- automatically on. But weak enough that at the far end of the venting trenches the fighters could get through the shields to make runs on the exhaust ports themselves. At the same time, strong enough that even shooting a proton torpedo at the port from
outside those shields wouldn't work. Neither would lasers, because ray-shielded. The targeting computer was having to calculate a solution on a target it had to make a right-angle turn to get to, over the curvature of the station's surface (over-the-horizon targeting). That Red Leader's
almost worked was very not bad -- just not quite good enough. Serious threading-the-needle shot.
It all seems pretty consistent. We've seen in the real world that things stagnate a bit during peacetime, while conflict spurs advancement. In the GFFA, peacetime artisanal craftmanship wasn't sustainable in a galaxy-spanning conflict, and concessions had to be made. At the same time, there was a technological arms race between sides. SO just because something worked during the Clone Wars, doesn't mean it'd still work against Imperial assets -- or First Order. We've seen some things in the real-world that are somewhat analogous. The US was set to retire the B-52 and the A-10... but the new technologies that were supposed to supplant those craft proved unable to perform as well, so those craft were retained. People were flying the same B-52s on missions in the Middle East that their granddad's had flown over Vietnam. The F-4 had no guns because, with "over-the-horizon" missile targeting, there would never be any more dogfights... until there were and we started losing craft and pilots left and right and had to bring back guns and dogfighting
in a hurry. The H-1 proved to be such a versatile foundation to work with that we ended up with variants from medivac to primary-assault.
Meanwhile, the Russian air force is so strapped, captured planes have been found to have portable commercial GPS units zip-tied to the panels because the installed units don't work. Something can
always be found in a pinch when you have to try to make something viable that isn't.