I mean - even based off your list - Poatan has beaten 5 champions...Izzy has:
Whittaker 2x
Yoel
Poatan
Cannonier
Costa
Vettori 2x
Gastelum
Poatan has:
Adesanya
Jiri
Hill
Jan
Strickland
I think Rob twice, Cannonier and Yoel are more impressive than any of Poatan's wins, other than Adesanya ofc. Alex did do work in 2 divisions and got a second belt, which counts for something for sure, but he hasn't done enough. Before anyone says anything about "former champs" it doesn't get much weaker than Hill, Jiri, Strickland and Jan for champs lol, good fighters of course, but c'mon now
Izzy has beaten how many?