Many problems come from TB mode. The others come from Larian design of combat (always outnumbering and outleveling you).
DOS 2 was much worse, believe me.
Turn based games should only feature difficult fights, IMHO, because combat is just too slow and boring for trash mob fights. There are already fights in the EA that made me listen to podcasts.
I get that this may break immersion, but to be honest, immersion is not a thing in Larian games. It is not something that they are going for. BG:3 is, to a lesser extend than DOS:2, but still, a collection of random fantasy cliches, set pieces that are riddles, waiting for players to use all kinds of shenanigans to manipulate them.
From a gameplay design perspective, DOS:2 and BG:3 are like BG:2, if BG:2 had only consisted of Weimer's Tactics mod and were only about challenging power gamers to come up with new ways to cheat the game engine.
