You don't have to think too much of Wilder's ringcraft in boxing but just know that if he decided tomorrow to transition to MMA he'd still be the most decorated male striker to enter in or near his prime in UFC history and easily one of the most decorated in the entire sport's history regardless of division. He'd also automatically become the most dangerous fighter, and by a wide margin, to ever compete in the sport regardless of discipline.
Ngannou is a very scary fighter by MMA standards, Wilder is extremely scary by any standard of striking. He would honestly make that 'lion' look like a domestic house cat by comparison. Just visualize the Stipe fight for evidence of that. In the same scenario, had Stipe been on the end of Wilder's punches instead of Ngannou's (who failed to put him away), then it would've been a one-and-done affair. Under the same circumstances he would've immediately folded Stipe up like a cheap lawn chair in disgusting fashion with the very first right hand that touched him.
Even despite his obvious shortcomings he's had a huge degree of largely unexpected success at the highest levels of both amateur and professional boxing. Not only did he medal at the Olympics as an amateur he also managed to beat some genuinely elite world class operators with some very impressive credentials. Just being big and athletic isn't why he was able to achieve all of that success though it obviously helped his case considerably.