In my career I've seen endless examples of hopelessly badly designed software where no amount of optimization can turn it into anything other than a piece of garbage. Slow, bloated and inefficient.
Ascertain an issue is too late for bad software. The technical term is polishing a turd.
Not that what you're describing doesn't happen, people trying to make something irrelevant fast, but that's not the big problem we face as an industry. The problem is bad software.
Hurray, bad software is bad, we did it! Just don't write bad code!
Before you write code you design (and/or architect) a system (formally or informally).
There's too little appreciation today for a well designed system. And the "premature optimization" line is often used to justify not thinking about things because, hey, that's premature. Just throw something together.
Like everything else there's nuance and a range of appropriate behaviors. It's probably worth spending some time beforehand designing the next mars rover's software but it's real easy to get, say, the design of an ai based program editor wrong if you aren't getting user feedback.