TLDR; https://jamespotz.github.io/blog/how-to-fix-wsl2-and-cisco-vpn, but certain internal resources are still not available after doing this (in case u need them re-anyconnect), others are though. toggling the metric priority is key here as well.
This and followup posts (even an automation) probably work as well, haven't tested yet microsoft/WSL#5764 (comment)
Also this could work, not tested yet as I did not check the sources https://wheatevo.com/wsl-2-vpn-routing-fix/
The article on msdn doesn't seem to apply for my case (wsl2, cisco anyconnect vpn)
I have some articles tagged [wsl2, vpn, wsl2-issue] that seem to approximate an automatable fix (microsoft/WSL#1350 (comment) etc.), but one of them really provides a very fast fix serving as the very baseline of all automating: microsoft/WSL#5068 (comment)