I think that dos2 isn't too easy, or too hard, i think is too binary. With binary i mean that is too easy to switch from hard to easy, when you figured out the important things.
The entire games is wrapped around binarity, mainly due to the armor system. It's either 100% chance or 0%.
Imho the difficulty go through the same process, and it feels really hard when some understandings of the game mechanics are missing, and it feels really easy when these understandings are clear.
It's hard to balance, because it's not a scalable difficult, it's either 0 or 100, like the armor system. If you, for example, improve monster hp, dmg, or something else, i think the difficult would remains the same, with veteran players sleepwalk through the game and beginners struggle even more.
Dunno guys, i've the feel that there are very few things that could improve the difficult system.
One of these things, imho, is the lone wolf talent. It's totally broken, really. I try to avoid it during my playthrough because it really made the game ultra easy, even with one single character.
A nerf/balance of that talent it would be welcome.