Recently I have seen a lot of leaders put up policies on their linkedin walls saying they respect sane working hours, weekend holidays, encouraging personal time off and many more. This is a case of giving back what was taken from others but disguised as a perk. Working late and on the weekends had been baked into as a given thing for a lot of leaders. It gets equated to more effort which was presumed to end up in more productivity.
The mindset is infectious, a person who comes into the workforce gets subjected to late working hours and weekend work, it becomes imbibed into their minds and they repeat for other new comers. The idea continued to grow stronger by Lindy effect, with people promoting workaholics and thereby creating more workaholics.

There is a change in workforce dynamics. Two decades ago, knowledge work boom brought in jobs that elevated the standards of living. The upgrade in lifestyle was so big that people were ready to do what was asked at the workplace. Leaders who were used to manufacturing mindset jumped on the opportunity and took it towards a downward spiral. Eventually people who worked insanely long hours and weekends were seen as committed irrespective of the outcome they bring.
What changed now is the workforce that is entering the market, a good chunk of the workforce has a pretty decent standard of living and what they look for is quality of life. The long working hours immediately removes the quality of life aspect and hence a lot of leaders are scrambling to understand how to improve productivity without stretching the people.
It was never fruitful to prolong the working hours to get more done in a knowledge work situation, yet a lot of leaders held on to that opinion strongly and rewarded hustle culture. Now that there is not much option to hold on to the hours of working, people are forced to return what was never theirs and look for different ways to engage and improve effectiveness.
In the software world, focussing on developer experience will attract and retain talent while helping achieve goals in a sane and sustainable pace. This involves balancing standardisation vs freehand, homogenous vs fragmented tech, governed vs federated ownership along with information symmetry and clean communication.