> But when you hit that wall, it is hard to stop and convince people to use different patterns and systems. I've seen so many tables go from "it will only be a few thousand rows" to suddenly several TB and then people are looking confused when performance and db admin tasks get really difficult.

It's much, much worse in my experience to have to develop for the opposite -- working on a system that was designed for an imagined "infinite" scale that in reality like 100GB and a few transactions a minute.