Good luck with completely removing support to run 32 bit applications and all those 32 bit videogames (which is the vast majority of them). Or any other 32 bit application that won't ever receive updates.
I'd say serious gamers already switched from macOS to Linux if they don't want to use Windows to begin with. Simply because you can run DX11 games in Wine on Linux, but not on macOS. Borking 32-bit games would only accelerate this shift.
Sincerely, A person who uses MacOS and games on a console.
edit 01: [screenshots]
1) https://screenshots.firefox.com/YJvULhgFlPJKtpD1/www.humbleb...
2) https://screenshots.firefox.com/UMQMitQ4Rm4viSlv/www.humbleb...
edit 02: To play it in a separate tabs as per the scrots just take the key from the purchase page https://www.humblebundle.com/downloads?key=foobarXXXX and apply it to this url like so https://www.humblebundle.com/play/asmjs/ftl_asm/foobarXXXX
As a bonus this allows you to play it on any computer without logging in.
If you want to upgrade your OS, then you need to accept that it will change. This has been the case for all of recorded history.
Keeping macOS (or any OS, really) not updated, is not really an option... unless you're going to keep your computer airgapped.
You might accept to keep unpatched systems, or manage to use them in an airgapped environment. But for a lot of businesses that deploy fleets of Apple hardware, the problem is going to be much more tricky.
(then again, I can see this being an issue only for internally-developed VB6-style apps, which would take a lot of effort to be updated... commercial software like Adobe CS, or even specialist software is going to be upgrade, if not immediately in 1 or 2 major releases, and Apple backports important security patches)