Daemon instability does 132-256 damage per second.
Crumbling does a whooping... 10-21 damage.
You can outheal crumbling with a 0.1% heal aura.
One of these things is not like the other.
This is a problem because almost all undead units now have stats or leadership comparable to mortals, which is resultig in horribly uninteractive games, particularly in domination mode.
We are seeing it be a particular issue with vampire counts and tomb kings, vampire coast are somewhat hampered by their reilance on weaker chaff undead and ranged units.
Vampire Counts in particular are so oppressive in domination mode that global bans were recently introduced so they don't get played at all in tournaments.
So if you like playing Vampire Counts, should probably hope this gets addressed soon. Otherwise they will just never see play except against cheese plays in mulitplayer.