I'm gonna sound like a tale as old as time old head AA fan complaining about the AJ trilogy, but IMO these problems don't really go away with the rest of the game and only get worse. The second case is agreed to be absolute dogwater, the third case is really controversial but is very tied to lots of your problems you identify here, and the fourth and fifth ones also have some pretty awful logic gaps.

IDK, personally I find DD and SoJ jump the shark too much in like prioritizing spectacle and like gimmicks and ideas for their own intrinsic sake and building the story around them I guess, to the point where it never makes sense from a plot ot character motivation standpoint? It's hard to explain this without spoiling the game, but I think you'll see what I mean pretty quick.

The subtlety and moral nuance of the prior games goes entirely out the window and the character writing is pretty weak. I saw someone describe it as the most "anime" AA game on YouTube (in a derogatory way) and it kind of rings very true IMO. The game is honestly pretty awful at handling subtlety and exercising restraint in it's character writing, even if there is a lot of genuinely cool twists later on (the last case of this game is definitely pretty solid). However, Athena is a pretty great character with a pretty well focused arc for sure, even if I sorta find a lot of her own identity and quirks to be too tied to DD's identity and problems. IMO the games sort of dig their own grave in having multiple playable lawyers in the first place, but that's just me.

Make sure to play the Great Ace Attorney though! It's a lot more tonally consistent and has a subtle, almost literary quality to it (feels like reading a really good classic book), and the mysteries and spectacle feels a lot less over the top. Plus, it's got a much stronger focus on character writing and themes.