I have setup so many instances over the months on different servers and the web ui always takes 40s to a minute to load per page I have always used redis for caching and the best methods even the aio docker image(s) are really slow.
kind of just been living with it for the past month or so but its really annoying when others are saying theirs takes seconds to load.
Uhm, you will need to tell us more about your hardware or setup.
I wouldn't describe my Nextcloud as especially fast or optimized, but it is only around 20s from the login screen to being able to use it. And once you are logged in it is quite fast.
i have used all sort of hardware from a pi 4 to a vm on dell server with 2 vcpus and 8GB ram and now a vm on a custom server with 4 vcpus of a AMD Ryzen 9 5900X and 8GB ram using the docker aio I havent messed with it yet because i expected it to work