Because a 20% drop in efficiency is substantial, and because the alternative to diesel generators isn’t just CCGT. You could also use solar, wind, nuclear, tidal etc etc

Carbon output of a diesel generator is horrific compared to just about any form of large scale energy production.

To be fair, I've seen devs use 1000s of times, even millions of times the resources required.

It usually all goes wrong the moment someone is granted permission to use a 2nd computer to solve some problem.

If you're allowed to use a second computer, you need at least 4 to match the performance you previously had on the single machine.

http://www.frankmcsherry.org/assets/COST.pdf