I'm in your same situation and I think it really depends on your use case. Are you creating an API that's read-only and only for you or a small internal team? You could pretty easily write that in just about any framework (or even no framework at all).
Once you start adding on features like allowing writes, authentication+authorization, rate limiting, API discovery, client library generation, OAuth support, etc then something like DRF really makes sense.
DRF is pretty darn flexible and it uses Django so you get a lot of functionality for free, including the Django admin if you want a way to explore your data. DRF in no way forces you to use the Django models (or even any models at all).
Once you start adding on features like allowing writes, authentication+authorization, rate limiting, API discovery, client library generation, OAuth support, etc then something like DRF really makes sense.
DRF is pretty darn flexible and it uses Django so you get a lot of functionality for free, including the Django admin if you want a way to explore your data. DRF in no way forces you to use the Django models (or even any models at all).