32 bits was dropped this year, not a decade ago. That killed hundreds of macOS games.

Another major issue is broken OpenGL: bad drivers, very old version and nowadays deprecated.

In 2010 macOS gaming was in a good spot. Nowadays, Apple is making sure you don't use Macs for games.

No, 32bit hardware was dropped a decade ago. There has not been a Mac sold that isn’t capable of running 64bit software for even longer.

32bit was dropped in Catalina, the prior release a year earlier started making it clear it was going away.

Neither intel nor amd sell 32bit only desktop processors, and possibly not even laptops.

Game developers complain about performance all the time, but given simply recompiling you 64bit gives (IIRC) a 15+% perf win it continues to amaze me that devs insist on producing 32 bit only software.

32-bit hardware has never been dropped. All your Macs are capable of running 32-bit. In fact, they can even run 16-bit operating systems.

It is software support that was dropped in Catalina.

"Simply recompiling" for games is impossible for technical, legal, financial and other reasons. Some companies do not even exist.

I started developing an iOS client for an API we use at work recently. Downloaded Xcode again, built a small POC Mac app and ran it. It wouldn't run because I am still on Mojave and the default settings are to build for 10.15. I was a little shocked/not surprised to get a "This application is not compatible with your software" type dialog from my own brand new code!

I really like a lot of the ideas that Apple implements, but the upgrade treadmill is notorious and not one of them.

You can write applications that run all the way back to Mac OS X 10.6 using the latest Xcode. However, our of the box a new project is going to be configured to build for the latest macOS supported by the version of Xcode you’re using. It’s very easy to set your deployment target to an older operating system though.

Yes, you're absolutely right and this is not generally a problem (although obviously APIs get deprecated, etc). All my projects have a cycle, though, where I open them back up and have to turn several knobs in the build settings to get them to build. It's not often an issue with the code aging out, but the Xcode configuration. I got a pretty good chuckle when that happened to a brand new project right off the bat.

Metal?