Start bottoms up, give away free or low/no margin services, gain adoption, capture the market, then with the pressure to grow, they start moving upmarket, go after 100K+ deals and raise prices, and eventually price out / fire vast chunks of their early adopters.
Been personally bit by this a few times, so these days I tend to very cautious about adopting non-organic software, at least not without a backup plan.
I’m a founder myself and this is one big concern I have about raising VC funds. Wrote about this here recently: https://typesense.org/blog/why-we-are-not-raising-funds/
I’ve also started to use the term customer-funded (similar to VC-funded), instead of “bootstrapped”, since the latter seems to give off an impression of early stage whereas the former is a conscious choice and state of being.