What use case in the year 2019 is made easier by UTC getting leap seconds instead of treating it as a monotonically increasing scale (TAI)? I'm genuinely interested. The only suggestion I have ever heard is use of a sextant -- what an anachronism in the modern world...
I'll add in; astronomers like to be able to find objects in the sky using calculations based on time. UTC (actually TT, which underlies UTC) is good for that.
Spend a little time on the various wiki pages for time standards, and think about why those things exist.
Your noon example works for a single longitude in a time zone and the time between subsequent noons on two different days will only be exactly 24 hours 4 times a year. It seems unnecessarily complex to push annual leap second updates to preserve something like as obscure as these 4 events for the 24 time zones exactly on the line of longitude to the accuracy of a second.
See the Wikipedia on abolishing leap seconds, "that the drift of about one minute every 60–90 years could be compared to the 16-minute annual variation between true solar time and mean solar time, the one hour offset by use of daylight time, and the several-hours offset in certain geographically extra-large time zones"
I believe you are actually converting to Terrestrial Time. If there is a correction of TAI+32.184 seconds in your calculation, that would indicate 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.
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.