I am about to downgrade my 2015 MacBook Pro from Monterey to Catalina as I am typing this...Catalina was a bit of a dud but Big Sur and Monterey surpassed Mojave in performance in my experience with Intel Macs. The only reason to use Mojave or earlier these days is for 32-bit support.
It made me think about trying Big Sur on my device since that is so far the only one I have not tried... I have tried Mojave and Catalina on a Dell Hackintosh before and High Sierra, Mojave, Catalina, and Monterey on my 2015 MacBook Pro...
Big Sur will be out of support once macOS 14 is released in non-beta form and Catalina is close to a year without updates...