It sounds like you're exclusively looking at 'webdev' jobs, where, yeah, approximately nobody uses C.

Try embedded. Never had a directly embedded programming job myself, but see a lot of it from recruiters 'C/C++' as you say, but in embedded my adjacent experience is that there's not a lot of C++, that's more likely to be the tooling than the firmware or whatever itself. (Binary size & stdlib issues I believe, or perhaps merely dogmatic assertion that that's the case.) Not to say it can't be & is never used of course, it can be and is.