I would, and have, argue that estimates and time tracking are, in general, wasted effort.
If you have good priorities, estimates are irrelevant, because you'll be working on the most important things, and that is unlikely to change no matter the estimated effort. If you don't have estimates, then you don't need time tracking to see if your estimates are correct.
You've just eliminated half of the overhead for software development - the only added cost is that you must continually understand and update your priorities (or values, if you prefer), which you should be doing anyway.
If you have good priorities, estimates are irrelevant, because you'll be working on the most important things, and that is unlikely to change no matter the estimated effort. If you don't have estimates, then you don't need time tracking to see if your estimates are correct.
You've just eliminated half of the overhead for software development - the only added cost is that you must continually understand and update your priorities (or values, if you prefer), which you should be doing anyway.