I can remember that in DOS1 it was quite possible to get 80-100% resistances to fire, ice, electricity, and earth simultaneously, simply by buffing your equipment with elemental essences (or rubies). Also a lot of stuff gave immunities to the CC conditions. So, you could basically ignore all surfaces and enemies that deal spell damage (except poison and tenebrium).
The popular opinion (at least in this forum) that the armor system sucks, seems completely wrong to me. Maybe that has to do with "The Anchoring Effect". I played the game before getting to this forum and I think it is awesome. In our group it leads to actually strategizing like asking our mage to focus an enemy with low magic armor. Maybe that is trivial, but I like it.
The thing about surfaces is that they deal little damage if you are only standing in them. I think that is good, otherwise I would have died so many times. However walking through surfaces is dealing a huge amount of damage. It's just that everything and everybody has a teleport, so it doesn't happen very often. (Heck, even the lv3 alligators in Fort Joy had a teleport...)
So yes, mobility is a bit too much. Another thing is cursed which gets out of hand. I guess 90% of my encounters end with everything covered in necrofire. That is because it cannot be overwritten and is easily created. I would like to see some changes to that.
