I suspect many (or certainly some) of your fellow academics share this feeling — even if they are unable to articulate it as clearly (in part, due to lack of time!). Busyness has become a moral good, high productivity a badge of honor. So, high-achievers find themselves (ourselves!) trapped in pursuit of an elusive reward that (of its nature) will remain always just out of reach. We can never write enough, do enough, achieve enough. There’s always more that we can be doing. Except, of course, that we’re only human, and there are only so many hours in the day (week, month, year). And, as you say, being constantly too busy to enjoy the fruits of our labor “defers the benefits of that work to some mythical after-life.”
I write this as I head into the home stretch of what has been the busiest term in my professional career. Tomorrow, I head off to a conference, where I’ll give my fifth talk of this semester. I am looking forward to seeing people, but the prospect of more days spent in planes and airports (during which I invariably try to catch up on work, another goal I will never reach) does not exactly fill me with delight. Once I get there, though, I think I will enjoy it. I usually do.
For the last decade or so, conferences have become my vacations. They’re working vacations, but they do at least get me out of the office for a little while.
All of which is to say: I sympathize. And I think you’re even busier than I am.