Comment by nullc

As a sibling comment says it already differs by about 30 minutes over the a year. And it will take roughly 4000 years for the mean solar time to drift about an hour--- so thousands of years for the mean time to dominate the error.

This makes getting a fairly accurate solar time arguably easier, in fact, because you can use a formula correction on top of a stable timebase without first backing out leapseconds which may or may not have been correctly applied.