I'm not sure that having your expensive software engineers not work 2.4 days a year is very palatable

They already don't work for 130+ days of holidays, weekends, vacations and sick leave. What's another two days?

Probably I already ask them to spend 2+ days attending HR or compliance training or listening to senior management tell them about sales targets.

But the point is, that 1% extra productivity requires the sometimes staggering cost of making the software 10x or 100x more reliable.

They have other stuff to do that's not bottlenecked on push/pull/CI. 1% github downtime should reduce productivity by a lot less than 1%.

There are n services and n tasks, the chances of overlap are minimal. In most cases people take a much needed break during downtime.

I fully agree with this take. We need to ensure we get every hour of work from our expensive engineers. This is why we got rid of coffee machines and bathrooms and moved to intravenous caffeine and other fluid drips and catheters. We cannot afford to lose productivity.