Personally, I don’t mind it too much as I’m able to deal with it and get kills done, but for sure this approach is pushing many players down the path of top meta and burn them instantly instead of finding ways to deal with mechanics, which could be so much more interesting.
Edit:
Also while I get this as a stop-gap, I don’t think locking a boss’ health bar at 5-10% until they get a chance to do their mechanics is the best long-term solution for this 