I understand that companies with enormous data sets can't afford to use joins at all, but I've yet to work somewhere where a properly indexed RDS/Aurora db wasn't able to make use of them just fine. Almost all of my queries beyond simple CRUD reads rely heavily on inner/right joins, and last time I spoke with someone at Fauna, they said that their query logic wouldn't be able to support what my query was doing.

I'm rooting for DB alternatives, but unless a new contender can be as unconstrained as an RDBMS, it's very hard to move.