So if you want to use it for gaming and have and AMD or Intel GPU and not an NVidia one, you’ll have to stick to Ubuntu’s outdated Mesa and kernel drivers.

This is not true. Pop OS packages its own kernel and often the kernel version provided by pop is upstream of the Ubuntu version. It is only recently that they have fallen behind ubuntu because they have diverted their resources to creating the Cosmic DE.

Edit : Also to be noted is the fact that being on the latest version of mesa is only necessary if you have very new hardware which may not be supported well(or at all) in the older versions of mesa. I for example have an RDNA1 gpu and saw no performance difference between mesa 22.5 on pop os and mesa 23.1 on endeavourOS. People using RDNA3 or Intel Arc may see massive performance/stability difference because these are very new hardware and drivers/optimisation for these current gen GPUs is ongoing