Job market for IC is most of the time quite easy if you are technical, developers are usually spending 2 years at a company. I don't see C-level people switching companies on a whim and work one company for many years (not everyone is Elon Musk).
Once you have C-level on your CV good luck finding job again on lower level or the same level but different company. My boss is in it for life with current company, I can put my notice tomorrow and I walk away like I never worked there.