[matz1]

>but often spent time on their phones and repeated experiments mindlessly

For some people this is called breaks.

Yes, you shouldn't do 12 hours full working, you should take sufficient number of breaks in between.

This will fit the 996 system.

[jpking]

You could look at it that way. Hours of time would be spent like this toward the end of the day so why not just go home?

In addition, mindlessly repeating experiments isn't a break.

[matz1]

During breaks you can go home as well

What constitutes a breaks of course different for each person. Maybe some prefer go to gym instead or going for coffee, or simply just strolling around.

[colejohnson66]

> During breaks you can go home as well

Not always true. In the US, you can be required to stay on premises, but it must be paid.