Many Emacs functions are sluggish on my work Mac, but I found out that this is because the Cisco endpoint security software stops and checks every binary that runs, every single Goddamn time, which means that things which shell out, like M-x compile and anything in magit, are noticeably slower.

I had the same issues. I mainly use Doom on my linux machine, but on mac it is distractingly slow. d12frosted/homebrew-emacs-plus seemed to reduce the lag, but I've had other issues with it, so have gone back to vim.