That is an extreme case though, I didn't mean that all optimizations are always worth it, but if we look at marginal value gained from optimizations today the payback is usually massive.

It isn't done enough since managers tend to undervalue user and developer time. But users don't undervalue user time, if your program wastes their time many users will stop using it, users are pretty rational about that aspect and prefer faster products or sites unless they are very lacking. If a website is slow a few times in a row I start looking for alternatives, and data says most users do that.

I even stopped my JetBrains subscription since the editor got so much slower in an update, so I just use the one I can keep forever as I don't want their patched editor. If it didn't get slower I'd gladly keep it as I liked some of the new features, but it being slower was enough to make me go back.

Also, while managers can obvious agree that making developer spend less time waiting is a good thing, it is very rare for managers to tell you to optimize compilation times or such, and pretty simple optimizations there can often make that part of the work massively faster. Like, if you profile your C++ compiler and look what files it spends time compiling, then look at those files to figure out why its so slow there, you can find these weird things and fixing those speeds it up 10x, so what took 30 seconds now takes 3 seconds, that is obviously very helpful and if you are used to that sort of thing you could do it in a couple of hours.

Many of us do frequently argue for something similar. Take a look at Casey Muratori’s performance aware programming series if you care about the arguments.

Maybe we should, all it took was Figma taking it seriously and working at a lower level to make every other competitor feel awful and clunky next to it then it went on to dominate the market.