The number one thing preventing builds from being viable is the vulnerability debuff. The builds that are viable are ones that can constantly have this up. Why is that? Because it’s a major multiplier in damage. Imaging a fireball sorc being able to do their full dmg all the time because they had 100% vulnerability uptime, that would easily make them do 2-4x the dmg, thus making them viable.
The worst part about it is you cannot overcome the vulnerability dmg increase by stacking a ton of crit and +dmg. You could have 1100% crit dmg and 1000% additive dmg. You’ll do far less dmg than having say 1000% crit dmg and 900% additive and 100% vuln dmg. Vulnerability is dumb and needs to go away because it makes too many builds terrible compared to builds that have vuln on targets a majority of the time.