Executors - of which P0443R11 is one of the latest iterations - is poised to be the most fundamental library addition to C++23.

A Universal Async Abstraction for C++

By Corentin Jabot

From the article:

What is it about?

It is first and foremost a quest to find the most basic building blocks on top of which one could build asynchronous, concurrent and parallel code, whether it be on a small chip or a supercomputer with thousands of CPUs and GPUs.

This is not an easy task and has kept many experts and many companies busy for many years.