Right, but couldn't you have used the exact same words you just used to describe PoE, the game that was being critiqued?
What you said sounds great in paper, but it missed a special magic that existed with Fallout 1/2, Baldur's Gate, Icewind Dale, KOTOR, and the like.
As someone who 1) is a developer 2) has played through the Infinity Engine games more times than I can count, I'd like to offer my own perspective.
I think the combat felt "same-ish" because of a questionable choice in development - the idea (which was very highly touted) that players should be able to create all sorts of builds and they should all be effective, in order to overcome the cliches like "strong but dumb barbarian". The problem with making every build viable is that in order to do so, everything has to "work" if you invest enough skillpoints into it. And because you've already gone in a particular version with your character build, and because it's guaranteed to "work", you're placed in a position where those abilities will always be optimal. The lack of hard immunities is emblematic of this philosophy. I can't tell you how many enemies I was able to knock over through the course of PoE.... including flying spectral beings. Virtually everything was vulnerable to the same types of damage as well (or at least they'd suffer glancing blows) so almost never was I forced to choice between weapons or spells... I just went with the best I had at the time, every time.
Contrast that with Baldur's Gate, where the type of weapon or spells that can damage creatures like clay golems, gnolls, skeletons, mustard jelly's, rakshasa, vampires, etc. all varies widely. The high difficulty/danger paired with greatly varying immunities (and damage outputs from the creatures themselves) is what leads to tactical depth. In PoE I never had to consider what enemy I was fighting, because I knew my shit would just work, and the damage output of the enemies wasn't appreciably different (with a few minor exceptions).
Lastly, the neutering of save-or-die spells was unsatisfying and made combat less exciting by reducing the variance (which is what makes games exciting... nobody would tune in to the Superbowl if the best team won every single time).
But really, the lack of equally powerful/viable but different tactics made combat boring. To use Baldur's Gate as an example once again, you could approach a combat situation with entirely different but equally "broken" ways, which made multiple playthroughs so appealing. To again use a specific example, take the classic case of the mage Tarnesh at the Friendly Arm in, one of the first frustrating fights in the game. If you just play it straight, which you can, you're probably going to have to reload a few times to win, which you eventually will through sheer chance. On the other hand, if you have a wizard, you can cast shield and remove fear to complete negate the wizard's spells. Or, you could position a thief directly behind him to backstab him when he goes hostile. Or, you could use a Priest of Helm to use his True Sight and get rid of the mirror images, leaving him defenseless. All of these make the combat trivially easy, but because they're not obvious to the first-time player, they're great solutions that provide an "aha!" moment when executed. That experience is called... "fun".
In summary: little variance in creature vulnerabilities combined with little variance in creature damage/abilities leads to same-ish combat. Toning down save-or-die spells also hurt. Finally, there weren't many viable but completely distinct approaches to combat, which was a problem.
I loved PoE, but the combat could have been improved.
