Embedded Linux/Application work might be an option. If you've got good core c++ skills and you don't mind learning new things quickly and on your own, then you should be able to handle the job just fine.
Actually, just yesterday I had a recruiter call where they remarked "oh we thought you had embedded experience but I guess not" and proceeded to get a rejection email that same day...
I am not that great at C++, but I guess self-teaching C++ is a more fitting path to go down vs. self-teaching backend tech?
I think it's more 'figure out what YOU want to do' and optimize your resume and job search for that. Recruiters will be somewhat random no matter what you do, so don't put that much stock in their comments.
I am not that great at C++, but I guess self-teaching C++ is a more fitting path to go down vs. self-teaching backend tech?