If things aren't nerfed, the only way to keep the game challenging is to overbuff the enemies. The current stage is an example where enemies are now just using Source Spell on you in an attempt to perma deal way too much damage and just CC you to death with a cheap shot.
One thing Divinity suffers from at the moment, is how easy it is to cheat the game by permaccing whoever is tough while also killing a certain key target right away with some initiate, teleport and bow+knife.
Certain stuffs do need to be buffed but the most powerful option should not be treated as the baseline. When everything becomes too powerful, the game overall strat turn into "Which side can cheese the other more" and it ruins those who try to be creative with their build.
Like, currently, you can do Haste -> Sneak +Snipe at the start of the fight and with some initate, shoot 2 more crossbow arrows with Adrenaline at the start (and in total, pretty much instakill anything that isn't a boss if no miss). They counter this by forcing ambush instead where you can't preposition properly. You counter this by using quick load so you can position first before triggering the fight. There's no real valid strat here because it's a cheese vs cheese. If you don't counter how the game cheese you, that Chain Lightning will just rekt your own team.
