There's another benefit to using a tenant_id. You can partition your tables using Postgres partitioning. That keeps the tenant's data together and keeps queries fast.

It's also amenable to distributed processing if you use something like Citus.

I'm really looking for an alternative to Citus, though. Citus itself is a bit tricky to use, and the SaaS version of it is owned by Microsoft, which means Azure-only. Also, Microsoft makes the SaaS version insanely expensive. If they had Citus-like features on Amazon Aurora I'd be there in a heartbeat.