https://www.timeanddate.com/time/negative-leap-second.html

Total forces set the general trend and in a thousand years or so we would have to deal with the fact that using 1970 definitions of 1 second = do many vibrations of a cesium atom and 1day = 86400 seconds, we would need to add a leap second almost every day.

But over the shorter time frame there is substantially more variability. So much so that there was actually discussion of a negative leap second.

At that point the big tech companies really put their feet down and said "enough with this bullshit" because removing a second is in some ways an even more complex engineering task than adding one.