The ability to run a cron every few seconds is pretty cool and avoids those OS cron scripts that loop and sleep, so I'm glad that was added. Only downside to cron jobs running inside postgres is PL/pgSQL. It's never my first choice for scripting sql operations. I'd much rather use python, ruby, etc. I'm glad it exists when there's no other option, but it's kind of its own beast.
That said, I'm very happy to see more and more stuff coming from Citus. We're looking to split a few growing databases and a bunch of folks are excited to try Citus again now that the enterprise features have been open sourced.
You can use PL/Python no?
I dunno about other hosted Postgres providers, but not on AWS RDS no, as the Python extension is untrusted. Looks like you can use plv8 via pg_tle (Trusted Language Extensions) [1] though.