I’m a working software developer, and if they prove they cannot do better, I get people who make statements like GP quoted demoted from the decision making process because they aren’t trustworthy and they’re embarrassing the entire team with their lack of critical thinking skills.
When the documented worst case is 5x you prepare for the potential bad news that you will hit 2.5x to 5x in your own code. Not assume it will be 10x and preemptively act, keeping your users from installing three other games.
Well, then I'd like to work where you work. Hard to find shops that take performance seriously. You hiring?
In my experience it's always been quite a battle to spend time on perf.
I'll happily take a demotion if I make a 10x performance goof like that. As long as I can get promoted eventually if I make enough 10x wins.