If that is indeed the build you are using, then this is entirely a skill issue. So no, I’m not wrong lol.
I also don’t use any generator on my ice shard build, and I have zero mana issues on that fight, so either you aren’t upgrading your gear, your lucky hit chance is terrible or you just have terrible stats in general.
There are sorcs that have cleared the 2nd capstone at level 58, I literally solo cleared it last night at 60, It is by no means as challenging as you are making it out to be.