I have both games and to me its not even a contest. Solasta plays like an indie mobile phone game. Its ok for what it is, Im by no means hating on it.
Baldurs Gate 3 feels like a major AAA title. It looks beautiful, has an engaging storyline and interesting characters.

Mechanically Baldurs Gate 3 feels more intuitive. The UI is smoother and easier to grasp. The targeting is way better. On ranged targets BG3 will tell you if your target is blocked. If Solasta does this as well, I have yet to find it. But Il also admit I have hundreds of hours more invested in BG3 than Solasta.

But I suppose thats because BG3 grabbed me and Solasta really hasnt.

Ive heard Solasta is more true to D&D 5th edition. Thats cool, I dont really care. To me BG3 is far and away the better game.