In your second paragraph you mention trying to be as productive as possible during your time off. Seems like you'd be setting yourself up for disappointment there. If you instead approach that time off with 'whatever happens, happens' approach you'll be more forgiving of yourself and may actually be able to relax so you can be more productive later.
The theory I'm exploring is that happiness is healthy. By living happily, perhaps I am repairing whatever damage I did when I was so intensely on the career grind (it was rewarding but, ultimately unhealthy in a burnout way). And, by doing that repair, perhaps I'll be better suited to be even more productive.
Or by more productive, are you referring more to building more dams rather than working more?
If you’re a software developer (or a plumber or a CPA etc) you can always get back into the workforce after some amount of time. If it takes you 1 year to leetcode and find a new job, you just need to keep 1 year of expenses as cash on hand.
Tail risk is a different story, but you can spend your whole life working and not save enough to handle all tail end scenarios
I just... yeah, don't find it satisfying when I've had small tastes of that life. I like to be able to look back at the journey and see how it led to growth in my skills and achievements I'm proud of showing off.
You can then pick up new hobbies, or just return to old hobbies with renewed enthusiasm. You can do things that matter even if they're of no economic interest. You can hone skills that aren't career-related.
I think that it also requires a shift in values.
In my working life, I've only ever taken about a month off at a time, but every time I've taken a longer break like that, I end up ultimately feeling dissatisfied with myself. I go into it with what a I think is a reasonable list of chores/projects that I want to make progress on, but ended up just puttering around— paradoxically, I get a lot more done when I have short bursts of time and have to force myself to bite off a manageable chunk and actually see it through.
I've heard people argue that a few weeks just isn't long enough to trigger productive restlessness, and that's why a sabbatical is more like 6-12 months. But this is what I worry about for myself if I were ever in a position to retire young.