I think if a fighter spends so much time lifting weights and drinking protein shakes, which is counterproductive in boxing, something definitely off with his psyche, some complexes / insecurities
I think that relatively high percentage of customers ( ppvs and tickets buyers ) loves to see muscular, more close to bodybuilders look lads. This maybe is reason. In modern days looks that the more well known and likeable for large mass with casual ppl you are, the more $ you might get. YT star vs wrestler in boxing match too had been done and with great success. Why not?
Like wladmir, hes an athlete not a fighter. He doesn't have that much "dog" in him. As small as usyk is he might be able to stop him just by accuracy.