The problem isn't with just nerfing, it's that they did literally nothing to adjust gjall properly for it. They still attempt to saturate the area with bile shots, meaning that they rarely aim directly at you, but they don't know they cannot shoot twice, so they just miss with the one shot they have, and when they rarely land a good hit, it's quite literally half of their previous potential damage output (minus some burning overflow since it doesn't stack I think).

Their combat loop is also unaffected by the removal of their second shot, leading to large time windows when they do nothing. You can even melee them now if you are at elevation, because they are so pathetic.

https://www.youtube.com/watch?v=IJAUHpACwjE

And it's the same thing with seekers, especially inside dungeons and overworld ruins. They are almost completely lost.