Longer waiting times can decrease productivity a lot more than just the runtime increase. If a program takes long enough that the user switches context mentally

Longer waiting times can decrease productivity a lot more than just the runtime increase. If a program takes long enough that the user switches context mentally, or goes to get another coffee or looks at a few posts on social media that now means far more wasted time. Humans are not robots and won’t just keep staring at the screen. Also a lot of simple optimizations could save seconds or minutes in the lives of millions of people, and across multiple devices/programs that adds up. Microsoft once sped up the booting process of their consoles by 5 seconds, by simply making the boot animation shorter by 5 seconds. Those consoles were sold to millions of people and it took MS 8 years or so to make the fix. That’s many lifetimes wasted once you add it all up.