I would never say that self-hosting anything is trivial. Linux administration, tuning, and troubleshooting can be learned, obviously, and the same is true of RDBMS. Neither is a trivial skillset if you want to actually be able to run stuff at scale, though. There's a massive difference between 25 QPS and 25,000 QPS (TFA states ~40 replicas, and an aggregate of 1,000,000 QPS).

That shouldn't deter anyone from trying, though. You can't learn if you don't try.