We've on track to do something different before the end of 2035: https://en.wikipedia.org/wiki/Leap_second#Phase-out_and_futu...

Shifting to a leap-minute feels close-enough to me: We might get one every 50 or 100 years. A lot of us reading this today will never live to see a leap-minute, but it's close enough that we'll still have it collectively in-mind when it it needs to happen. (And if we screw it up at that time, the outliers will only be off by a minute. Not so bad.)

A leap-hour, meanwhile: That kicks the can so far down the road that we'll probably lose track of it completely. ~6,000 years is a very long time; society will be a very different thing by then. Leap-hours seem to me to be moral equivalent to the "fuck it, let's just give up" option.

edit: accidentally a word, and fixed an off-by-an-order-of-magnitude error on the approximate years required for a leap hour