Had some pretty negative experiences with pricing/"enterprise" sales tactics by Okta (which now owns Auth0, and they used the same tactics on both products). I will take AWS pricing shenanigans over that any day.
Given the choice between a crummy API and being driven bankrupt by a SaaS vendor, I prefer a crummy API. I suppose your calculus might look different if you have a lot of money or an employer with great negotiating leverage.