Wondered this myself. That said, championships aren't what they used to be. There has been far more inflation of trinkets than even the most debased fiat currency. Hell, a belt is not worth a current Shiba Inu.
Fury was the lineal HW champion. Wilder, the WBC champion, walked second. Canelo was the lineal MW champion. GGG, the WBA, WBC, and IBF champion, walked first.