The easiest way to get more time is just to work for a large company that provides meals and doesn't make you clock-in and be hyper-efficient with your work so you can slide out after six hour days, but that's easier said than done.
Realize that people who are really physically fit treat it like a hobby, so if you think something is more worth it (writing, guitar, binge drinking with your friends), then don't stress about not accomplishing everything-- it was an intentional trade-off.
And the not really solution-solution is to have enough serotonin so that you're perfectly happy doing things like cooking, running errands, and working out-- which is a big goal of mine.
You wont remember the project, hell you'll probably forget the job. But the little snippets of things that happen in between working hours will stick with you. They are in effect your life.
Of course, working less in the future often times entails working more now. Not in the retire-early sense, which realistically only a few can hope to achieve. But in finding employment that supports and doesn't compromise your life outside of it.
I work a 30 hour a week salary gig that I negotiated. I have to work at a small company, but it's better than freelancing.
I also work 100% remote from home. People talk about feeling out fo the loop or whatever, but I play music with friends and have a family so it[s never been lonely for me.