It replaces the need to install docker and mess with a lot of hackery instead with an officially first party supported linux container subsystem.

Edit: and since I forgot to mention a key value-add of this is that it's integrated with group policy, defender etc so you can limit specific users or groups or OUs, etc to running specific containers or to exposing specific resources/network devices/hardware/etc to WSL at all. It makes managing all of it no different than managing any other part of an enterprise windows setup.

And likewise WSL has native antivirus/anti-intrusion instrumentation hooks via a Microsoft Defender for Endpoint/MDE plugin to WSL so that unlike with docker, etc you don't get a sudden blindspot that's non-trivial to monitor (or that comes with a heavy perf penalty).