Thurman literally does everything better than Wilder but Wilder is considered, by many, to be a much greater fighter. What makes fighter A a greater fighter than fighter B when fighter B has a much better overall skill set.
Honestly, there are quite a few boxing fans out there who considers him to be a great fighter, but there is also a lot of boxing fans who just consider Thurman to be good.
Thurman fights? 4 fights in 4 years is why nobody really cares about Keith Thurman, he's on his way out, got shook a few times against the Riverside Rocky.
Wilder and Thurman have people to beat before they can achieve greatness. Wilders got Fury and Joshua for the most part, and Thurmans got Crawford and Spence holding on to his greatness belt.
Wilder has stayed more active and has looked spectacular in doing so.. Thurmen had a signature fight against Porter, but that was 3 years ago, and he has failed to capitalize since then
You know... sifting through hundreds of opinions to find one or two nutjobs that say Wilder is great, doesnt mean much. Nobody credible thinks that Wilder is great, yet.