I'm not sure I understand who this is for.

I get that Auth0 is filling a niche (a rather large one) where companies don't want to implement and run their own authentication and authorization, though I still don't completely understand why not.

But it seems this is Auth0's version of running a lambda, but why would I choose their service over AWS, Google, Azure, etc.

They seem to be headed toward an a la carte firebase. Is that the goal? Simpler than lambda, but less complete than firebase?