Yes, it is ultimately TT. The order goes:
UTC -> TAI -> TT
I could argue the TAI to TT is the second step. But let's put the pedantry aside: Is your best answer of something made easier in the modern world by leap seconds ensuring that solar noon happens at exactly 12:00:00 four times a year on an exact line of longitude for the time zone? And 4 times a year would require a time zone that does not honor daylight time, otherwise it is twice.
I'm not some crackpot here talking about the absurdity of leap seconds. US, China, Australia, Japan, S. Korea are on board for discussions about abolishing to happen in 2023.
> I'm not some crackpot here talking about the absurdity of leap seconds
No question about that; leap seconds have been controversial since they were invented. The question is whether "the juice is worth the squeeze" which is of course an opinion rather than a fact.
The nice thing about time standards of course is that there are so many to choose from. All of them have flaws when you try to use them the way we do in civil time applications.
I could argue the TAI to TT is the second step. But let's put the pedantry aside: Is your best answer of something made easier in the modern world by leap seconds ensuring that solar noon happens at exactly 12:00:00 four times a year on an exact line of longitude for the time zone? And 4 times a year would require a time zone that does not honor daylight time, otherwise it is twice.
I'm not some crackpot here talking about the absurdity of leap seconds. US, China, Australia, Japan, S. Korea are on board for discussions about abolishing to happen in 2023.