IMO, Solasta is a better game from a combat perspective right now, its smoother and hewing closer to 5e rules has served it well. It also has a better, and far more usable UI, with easier UX features, albeit the UI isn't super pretty.

That said, BG3 looks much better and has better dialogue. BG3 also has a better setting and full access to official D&D material, where a lot of the custom solasta subraces and subclasses feel quite over powered compared to the SRD ones

If I could have Solasta combat mechanics and UI with BG3 visuals,setting and dialogue. It would be a perfect game for me.