But my point is you won't ever hit this type of traffic. You don't even need Kafka to handle streams of logs from a fleet of generators from the wild. Postgres just works.

In general, the problem with modern backend architectural thinking is that it treats database as some unreliable bottleneck but that is an old fashioned belief.

Vast majority of HN users and startups are not going to be servicing more than 1 million transactions per second. Even a medium sized VPS from Digital Ocean running Postgres can handle that load just fine.

Postgres is very fast and efficient and you dont need to build your architecture around problems you wont ever hit and prepay that premium for that <0.1% peak that happens so infrequently (unless you are a bank and receive fines for that).