The communities playing old games did not need or want versions playable in the browser, they're already playing the games on emulators, source ports, or with community patches for modern systems.

Not as easy for graphically demanding games, but web browsers have been able to run a full VM in a browser for years now. Slap the game on it and call it a day: https://retroonline.net/Windows/Pharaoh%20%26%20Cleopatra

Now, please vibecode me a winxp directx driver that serializes calls to its wasm counterpart, to enable graphics acceleration for such VMs. Sounds highly doable: virgl, virtio-gpu and Venus exist. Might be even simpler to do it for Vulkan and port dxvk to XP.

and that's something desperately needed?