The ideas thing is very true and to be fair to Lucas, every ideas man is going to be like this. No one has 100% good/great ideas and it probably is more of an 8-2 split of objectively bad to good before taking into account opinion that makes “good” even lower.
And to be fair to Lucas, i do think he recognized this weakness which is why he asked prominent directors like Spielberg to direct the prequels. In addition to their expertise in directing and dialogue which would have covered his own weaknesses, he would have a trusted talented individuals to bounce ideas off of. I do think we tend to think of the top creatives as “mythological geniuses” who came up with so-and-so invention completely on their own (Steve Jobs, John Lennon, etc) when in reality they did have people to bounce ideas off of.
i do think Lucas is still bittersweet about Star Wars. On the one hand, its not his problem anymore and he doesnt have to incur fan wrath for things they dont like and he ensures his employees and family still make money. On the other, Star Wars is his baby. It was what made his career and is still all him. Althoigh Indiana Jones is his other top IP, that one is arguably co-developed with Spielberg and is not “all Lucas” in that sense. Well, no meed to feel too sorry for him since he is still a cinematic legend with wealth that will last beyond his lifetime.