The old system throwing chance in the equation added elements of surprise and unknowns. It allowed for the ability of combat to surprise you.
While I do not debate this, I absolutely DESPISE surprises. I like chess. And even better than chess, gearing and builds allow you to skew the odds in your favor such that there is no black-loses-white-wins, there is only "I beat this encounter because of my own effort and initiative", and adding chance into the equation completely drains that away. A solid win becomes a win because you didn't unlucky. A simple encounter, which could just be a challenge anyways in the new system, is potentially game-ending because of chance. Divinity has never been about chance. In classic, you came out the gate with multiple 100% CC's at your disposal, from Midnight Oil to Teleport. In EE, in honour mode, you had to bring similar 100% CC to the table, or else potentially forfeit your run. I don't find that "fun". I don't find that "tactical". I think it runs counter to the point of the game, and would vastly prefer encounters with enemies that can beat me of their own merit, that know the same spells I do and can use them to win, that have the same 100% chance to CC me that I have against them. There's a reason Divinity: Original Sin 2 is my favorite game already, and it's not even out of early access.