I think you’re wrong.
Cain
Brock
overeeem
werdum
Bigfoot
JDS
Rothwell
Browne
Schaub
Cro cop.
There were good heavyweights back then.
now there’s like 4 of them.
Brock saw MMA as a last resort.
Werdum was never athletic, just skilled.
Bigfoot was never athletic, just big.
Rothwell was never athletic, just weird.
Cain, JDS, Cro Cop, Browne, Overeem, Schaub.
Overeem and Cro Cop were from different eras.
That leaves Cain, JDS, Schaub, Browne. Three men who chose MMA not as a last resort who can be considered athletic in general.
What about now?
Gane's here because so many stars aligned. If that friend never said "yo come train muay thai with me", if Gane were able to pursue football/basketball, if he didn't go the MMA Factory to find training partners for muay thai and instead found a kickboxing gym or if he didn't lose his job, he wouldn't be here. If even one among so many things happened, he wouldn't be here.
Ngannou wanted to do boxing but he just happened to find Lopez, who convinced him to do MMA. He just happened to be a HW athlete as well.
That leaves who? Stipe, Blaydes, and Aspinall.
Bigi Boy is not athletic per se, just athletic compared to UFC HWs.
Lewis is not athletic, just powerful.
Volkov is not athletic, just lengthy and big. He's athletic, but not "in general".
Harris and Hardy are two other potentially "athletic in general" guys but I don't know if you count fringe top 15ers.
CONCLUSION: we're just as bad or as good as before in terms of attracting athletic HWs. IMO this sport will never go beyond this unless fighter pay is significantly raised. Then it'll hit another ceiling where the main reason would be big athletic men would still not want to fight in a cage for a living.