Ha, I've literally never heard of bottom, and haven't looked it up yet, but it's just kind of funny doing Linux/Unix forever and knowing almost exactly what it must be about, just given the name. I'll edit this if I was wrong, but I bet I won't be.

Perfmon essentially allows you to define commands you use daily, defined them in a toml file and tab them, ie customizable. It could be docker or kubernetes commands and so on. This is different from btm.

Bottom(btm) gives just more graphical than top.