BG3’s Devs didn’t feel like 5E was too shallow, iirc they said that their next game wouldn’t be 5E because it was too complex and they felt it didn’t correctly fit what they wanted in a game. Have you checked the divinity games? Their systems are much, much simpler than 5E is.

I’m hyped beyond belief for the next divinity game, Divinity, but I warn you, the game system will be much simpler.