Ngannou makes MMA look bad too in his UFC career, in exactly the same way.
I mean, he was a sand shoveller/wannabe boxer who came to the UFC and decimated highly experienced MMA fighters like Reem, Arlovsvki, Cain, Dos Santos - with basic wild scrubby boxing. He also became the UFC HW champ by 1 punch KOing someone considered the UFC HW goat.
So if he makes boxing look bad by running Fury that close, he made MMA look bad too when he started decpitating top 10 UFC heavyweights.
The reality is he's just a freak of nature, and overperformed in both sports.
By pure physical ability - freakish power, physical strength, chin - there's no doubt he could beat some top 10 HWs in boxing just like he did in the UFC.
I think that says more about Francis being a unique physical specimen, than it does about either sport tbh.