For smaller projects and locally, I'm running background services via a compose file... it's a few lines of configuration, and just works. Redis is crazy low hanging fruit.. even job queues that run over Redis make a bit more sense than with Postgres more often than not.
I'm far more hesitant to throw a more formal MQ in the mix though... mostly from experience in that a lot of mid level ("senior") developers don't really understand queues very well at all. Even if conceptually, using tables for queues is more complex.
That said, I will use PG for workflows similar to K/V, Document (JSONB) and other structures over reaching for say MongoDB, etc.
Of course spinning up a hello world of anything is easy. Now introduce monitoring, change controls, version upgrades, multiple environments and regions
It's not that it's necessarily complex. But if you don't need it, don't use it. The business could use your time elsewhere