Continuing from my earlier train of thought, in regards to Counterspell especially, the action economy means that in most practical cases in fights involving multiple spellcasters, it's going to be a far more effective tool against the player rather than equally effective VS players and enemies.
I had already seen inklings of this in Solasta - in some fights, a player would have to have one spellcaster bait it out with a lesser spell to prevent their second caster from having their major spell interrupted, and that's assuming there aren't multiple spellcasters in the enemy party capable of countering it. Meanwhile the opposite could be true in BG3, the enemy AI is likely to be devious enough to bait out our counterspells with mooks casting cantrips before the boss sends a fireball at us. At least in Solasta, the reaction system prevents enemies from baiting out your own counterspells in this way.
Sure, Larian could design encounters where there's only one fireball caster or counterspell user, but given my extensive experience with DOS2 and how it devolved into most fights having to be resolved within 3-4 turns or half your party was already dead towards late game, I don't expect this. I expect maximum pyrotechnics.
In fact, I can already think of a potential workaround for the problem of Counterspell in BG3 - turn it into a targeted spell that disables the next spell cast by the target. My faith is so low from a mechanical standpoint that this is probably the cleanest solution I can think of and the one Larian is most likely to implement, now that the hope for a proper reaction system is all but gone. And it's still completely inferior to normal counterspell.
