I'm not sure that Fury is technically superior to Usyk, but he is very much superior to him in physical strength. I can well imagine that Usyk will box with Fury on equal terms (and it seems to me that Usyk is faster than Fury), but I can hardly imagine that Usyk will be able to keep Fury away for all 12 rounds and prevent him from delivering his crushing blows.
I'm not sure, he's still a very technical fighter when it comes to it. The only problem with Fury is motivation, he's performed worse (Wallin) when he isn't motivated. If he isn't motivated his technique drops, as well as his power. He just looks like he's trying new things, rather than focusing on winning, He takes a lot more chances, now we kind of got accustomed to that because of the Wilder fight after, since he had to take chances, since despite how technical he was, one hit, and it's over.
The thing is I think Usyk despite being technical, doesn't carry the same knockout threat, and outboxing Joshua isn't exactly a massive achievement, in a technical way at least. Joshua isn't technical, and hes never been a traditional boxer like Usky, instead he won his fights because of his power. Now, ever since he was dropped by Ruiz, hes backed away from fire fights, which has been his undoing. He seems to lack that confidence he once had. If Joshua gets that back, I see him beating Usyk, but he will absolutely not out box him. Same with Fury, except I believe Fury could match him toe to toe in a technical boxing match.