He isn’t holding up the division. It’s a myth that anything gets held up when a ranked fighter isn’t fighting whichever up and comer people happen to wish they’d fight at that time.
Islam went from Bobby Green to a title shot.
As for Wonderboy specifically, his last five fights have been against Luque, Neal, Burns, Belal and Holland. I’m really not seeing what there is to complain about with that. He’s also 3-2 in those fights, which explains why he’s in the top ten. If you’re good enough to beat Luque, Neal and Holland, you’re a top ten fighter. There are also two grapplers in that list for what it’s worth. There’s a mix of experience and potential. It’s a perfectly respectable set of opponents.