This periodic adjustment mainly benefits scientists and astronomers as it allows them to observe celestial bodies using UTC for most purposes

This is incorrect, dealing with leap seconds is a major problem in astronomy, requiring a data file or even recompile any time there is a new one announced. Since they are only ever announced 6 months in advance, it creates a lot of logistical problems.

Astronomy algorithms usually work in Barycentric Dynamic Time, or Terrestrial Time, or UT1. In reality the whole invention of UTC is so that people don't have to deal with those systems on a daily basis.

The process most astronomy programs go through is to get the UTC from the user, convert the Gregorian date to a Julian day number to get rid of the Gregorian Calendar altogether. Then look up the number of leap seconds, add those to the JD to get International Atomic Time, then add 32.184 seconds to get Terrestrial Time. If Barycentric Dynamic Time is needed, you must first compute the velocity of the Earth relative to the solar system barycenter (which itself requires TDB), then compute the relativistic effects of that motion on Terrestrial Time. If you need UT1, these can only be obtained by observation from the International Earth Rotation Service, and required daily updates, and interpolation of values in between observations.

So, as you can see, leap seconds do nothing to make an astronomer's life easier. In fact, we jump through a lot of hoops to make the average person's life easier. It sounds like Meta wants to change the definition of time for everyone just to make their programming a little easier. I find the very premise just out right ridiculous.

It's true that your average person will not be affected by the Sun setting a few seconds earlier. But eventually it will build up enough error that it eventually has to be addressed, and Meta is just trying to make their problem someone else's problem.