Honestly as a long-tenured employee, I'd be more happy with a modest, capped N weeks / year, with an explicit XX week sabbatical every M years.

It's difficult to get that "hard reset" you need every once in a while with a 1-2 week vacation [which to be fair, is already fairly privileged], and even if you have 4-5 weeks / year ["generous by US standards"] it can be hard to take more than a couple of weeks at once because you need to save a week or so for Christmas, a few days for your anniversary, a couple of days for you or your spouse's birthday, three days to close out Thanksgiving, etc etc.