It seems that owners believe it is because stimulus and unemployment are a major discouraging factor. (No clue … Probably so). Paying enough to get over that can be a huge leap (again, no clue what the worker is facing in that case).
Whenever you benefit with a giant cliff or vehicle test attached to them, you get people who will resist passing that test for as long as possible. “I can stay at home because X or go to work for Y (> X)” put someone in the position to question “is it worth the work of Y – X” instead of “work worthy of Y” .
This is the main effect that can be minimized by things like real UBI. You do not lose benefits because you start work or exceed a certain pay threshold.