php 8 polyfill

At the moment, a PR has been added that implements a polyfill for the str_contains function from PHP-8.
I myself once wanted to implement something similar, but there is one caveat.
It seems to me that the best solution would be to create a separate package in the official repository with a polyfill for all string functions added in php-8 and add it to the composer dependency.

Why a package and not an integration into the core of the framework?
When the minimum php version for the framework is 8.0, the maintainers will not need to remove the polyfill from the core. They can simply exclude the package from the composer dependencies.