Just paying Hasura gets you just Hasura (at least before Neon it used to)
NHost gets you Hasura, the underlying postgres db, pre-configured auth with JWTs, blob storage, functions and a client-side library to get all of that working together with nearly zero configuration.
edit: also, Hasura's cheapest offering ($100 / month) is still prohibitively expensive for indie projects (That's just Hasura - you would have to add database costs, auth costs and blob storage costs to that $100).