This is 2015-2019 data; I don't think it's changed that much for EMG though.
If you do an hour/study without tech, definitely not worth it UNLESS you keep some of the technical component (which is pretty rare in employed settings). The professional component of the RVU's means that you are essentially losing productivity vs just seeing clinic patients (I think it's tilted even more in favor of clinic visits with changes since 2019).
If your in private practice and keep all of the technical component, then it is still worth it--the actual pay is about twice what you see with patients from what I've heard.
TLDR: EMG/NCS is worth it if you're in private practice, or if you're employed plus use a tech, have managed to negotiate keeping some of the technical component, or can do around a study/30 mins (which is actually pretty rare without churning out hot garbage).
Or just if you enjoy doing them and realize you're taking a bit of a loss.