True, and things that manifest only on old/slow hardware or on bad internet are the worst kind for this, since 100% of developers who have any say in the matter would never accept such circumstances at all, so they’re always approaching every issue with multi-gigabit speeds, zero latency, and this year’s $3,000 Mac. “What do you mean the page loads slowly?”
A customer of mine has the implementation of several API endpoints starting with a simulate_slow_connection method that basically sleeps for a random amount of ms. I think it sleeps 0 ms when running tests and definitely sleeps 0 ms in production. So it's never super fast even on $3,000 Macs.
