Since Wine 9.0, you can run 32-bit windows apps on 64-bits directly, without the need for 32bits distro support. It's called WoW64. You can read about it in here: https://gitlab.winehq.org/wine/wine/-/releases/wine-9.0#wow64.

It's not yet enabled by default and existing 32-bit prefixes needs to be recreated Arch is migrating to it

Native Linux games on Steam run on top of steam-runtime, a collection of libs (32 and 64 bits) running in a container called pressure-vessel. In theory they don't need 32 bits distro support.

Steam Linux client itself is 32-bits. Unfortunately

It's because of how memory works, that would be additional technically emulation level translation, since you woukd need to emulate 32 bit ram.

Note: this is just me guessing.