All military movies, covering pretty much all eras, do that simply because combat, esp. modern combat, happens much further out than what we see on shows and in movies. The reason for this is simple, to keep everything/everybody in frame. This is why in scenes involving infantry everybody is so close together when in reality everybody is yards apart from each other so that one grenade doesn't wipe out an entire squad. The same with tanks, you see them moving together just a few yards apart when in reality they'd more tens of yards apart for much the same reason as infantry. This will happen in Top Gun 2 for the same reasons, to keep as much as possible together in frame and to make things more exciting.I was flying home near Palmdale AFB and saw a F16 and a F22 playing cat an mouse. Both were leaving visible contrails. The F22 was running circles around the F16....it was an impressive show.
The problem with our current 5th gen fighters is that they kill from miles and miles away. But Im sure Hollywood will find a way to make it plausible (yea right).
There is also one thing that everybody is forgetting in this discussion about 5th gen aircraft and their capabilities are Rules of Engagement (RoE) and how that may very likely prevent F-22s and F-35s from attacking from maximum distance. In the first Top Gun the Tomcats easily had the same beyond visual range capabilities as our 5th gen aircraft do, remember, the F-14 was armed with the AIM-54 Phoenix with a range of at least 100 miles and was conceived as taking out Soviet bombers a loooong way from its carrier. In reality, however, they never had the opportunity to shoot down anything from long range, with the target being only a blip on the radar, RoE were (most often) like in Top Gun, do not fire unless fired upon. This is the easiest and most realistic way that they'll bring things into dogfight range, putting our heroes into hostile situation outside of a declared war where the RoE won't allow them to engage from max range. Also, one other thing, because of concerns of friendly fire and collateral damage Tomcats weren't allowed to fire at targets sight unseen and had to positively visually ID their targets before firing, this was aided by the addition on long range camera pods under the nose which allowed the crew to see their target from much further out than they could with their bare eyes.