It was an abandoned path even before 3.10, it just took longer to implement 649 and 749 than they expected.

But this is a "...will continue to exist with its current behavior at least..." is an important bit there.

From pep-0749:

     Sometime after the last release that did not support PEP 649 semantics (expected to be 3.13) reaches its end-of-life, from __future__ import annotations is deprecated. Compiling any code that uses the future import will emit a DeprecationWarning. This will happen no sooner than the first release after Python 3.13 reaches its end-of-life, but the community may decide to wait longer.
It has a good overview of the history.

https://peps.python.org/pep-0749/