Startup folks - How did you get ahead in your career after being layered?

I feel like this is a general problem that people who join startups in really early stages face. They get hired to do a function, then once the startup picks up, someone more senior gets hired and they’re practically demoted. This is happening third time to me, but still haven’t figured how to deal with it. The first time, someone from Stanford got hired and I felt really insecure about it. We got along pretty well but I couldn’t take that we were of the same age and this person was managing me despite me being around in the company for longer. That person left, my function was changed as well and again after a year, I was layered by another person. I just joined a new company four months ago and feel like the same thing is about to happen. I know they’re hiring someone. Makes me feel anxious about how I’ll lose ownership of things I’ve been doing and I haven’t even gotten the chance to prove myself yet. Do I just wait it out? Or talk to the founders about it? I understand where they come from, they do what’s best for the company. But I feel like I should look out for myself as well.