The biggest problem is that unless the main language you’re familiar with is PL/pgSQL, you’ll eventually run into the roadblock that is having everything reside in the DB.
In my case, I simply could not figure out how to use the Users table without having the password returned in all queries. I could turn off the automatically generated queries that Postgraphile made, but at that point why bother with it?
Other problems are that there isn’t a mature and well established method of maintaining development, staging, and production database schemas on projects with more than one developer.
Graphile makes https://github.com/graphile/migrate, however, it seems incredibly brittle and is built on a workflow that will absolutely break production if it is slightly deviated from.
I really liked using it! I just hope some of these developer ergonomics issues could be better handled.