How can you tell that you have completed quests?

I feel like I did them all. I’m level 91 and when I’m looking at the build I’m following online. I’m still missing 20 passive points.

What the heck am I doing wrong here?

you can check which one you got with /passives
you missing 12 points (lvl 99 - 91) so you really missing alot
don't forget annoints etc which gives you a specific keystone, might be also one you counted in