Ken Thompson and Dennis Ritchie created Unix on a PDP-7 in 1969. Well around 1971 they upgraded to a PDP-11 with a pair of RK05 disk packs (1.5 megabytes each) for storage.
When the operating system grew too big to fit on the first RK05 disk pack (their root filesystem) they let it leak into the second one, which is where all the user home directories lived (which is why the mount was called /usr). They replicated all the OS directories under there (/bin, /sbin, /lib, /tmp...) and wrote files to those new directories because their original disk was out of space. When they got a third disk, they mounted it on /home and relocated all the user directories to there so the OS could consume all the space on both disks and grow to THREE WHOLE MEGABYTES. And thereafter /usr is used to store user programs while /home is used to store user data.
source: http://lists.busybox.net/pipermail/busybox/2010-December/074114.html
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