From a recent HN discussion, I learned that emacs has had a sampling profiler built in — not on MELPA or something, first-party! — since about 2013. How many widely-used applications these days contain a facility for asking "why is the command I just issued executing slowly?" and for _doing something about it?_ As far as I'm concerned, that's now table stakes for a programming environment: you should be able to not just run a profiler on whatever program you're using the editor to interact with, but to do robust profiling on your editor itself.