After the first zone I felt like the combat in Divinity took a sharp dive down the cliff of boring samyness and piss easy difficulty; also next to 0 character build progression and a snooze fest of a story, but that's beside the point.
Not saying Inquisition is some perfect gem. It's got it's own truck of baggage, but if you pump the difficulty up to hard and/or nightmare you absolutely do need to use tactics for level appropriate content.
Mostly saying that Original Sin is not what I would consider some challenging rpg combat. Sure it starts off interestingly complicated with all the elemental interaction. But it then stays in the exact same place for the rest of the game. Any semblance of a "real challenge" quickly evaporated in my personal experience.
(tbh i feel like D:OS rode the nostalgia train like a honeyed cock, but it wasn't all that good of a game et all (and i pretty much grew up on your classic crpgs))