However I don't think it is something that will ever be done, designing a good standard library is quite difficult, especially by email and rfc.

I think it is better if the community designs one that gets a lot of traction to become de facto standard. All the large frameworks already has their own standard library.

With the performance improvements to PHP over the years it is no longer a detriment to performance to write a standard library in PHP.

And if we can get the operator overloads rfc passed we can have userland scalar objects

https://wiki.php.net/rfc/user_defined_operator_overloads