Yes, and there is nothing stopping you from doing this, as I already outlined. Your idea of what is important is entirely not my idea of what is important. "Updating old interfaces" means breaking backwards compatibility and old scripts - feel free to do that, but don't call it Perl.

To expect that such modules would be maintained by the Perl maintainers is too much.

IO::All is a horrible idea that opens up the locker of footguns that PHP closed a long time ago, by allowing open("http://..."). It would be a very bad idea to include it in the Perl core.

Also look at Python, whose Batteries Are Leaking. Having modules maintained separately from the core is important because the module release cycle is different from the Perl core release cycle.