What happens when apple switches to riscv, or depreciates versions of metal in a backwards incompatible way, or mandates some new code signing technique?
The attitude in the apple developer ecosystem is that apple tells you to jump, and you ask how high.
You could complain that Playstation 4 software is incompatible with Playstation 3. This is the PC gaming industry, there are higher standards for the compatibility of software that only a couple companies can ignore.
Apple will never transition to RISC-V; especially when they cofounded ARM. They have 35 years of institutional knowledge in ARM. Their cores and techniques are licensed and patented with mixtures of their own IP and ARM-compatible IP. That is decades away, if ever. Even the assumption RISC-V will eventually achieve equality with ARM performance is untested; as sometimes ISAs do fail at scale (Itanium anyone? While unlikely to repeat; even a discovered 5% structural difference in the negative would handicap adoption permanently.)
"This is the PC gaming industry"
Who said Apple needed to present themselves as a PC gaming alternative over a console alternative?
Consoles are dying and PCs are replacing them. Like the original commenter suggested, people want to run PC games. The market has decided that the benefits of compatibility outweigh the added complexity. On the PC you have access to a massive expanding back-catalog of old software, far more competition in the market, mods, and you're able to run whatever software you want alongside games (discord, teamspeak, game streaming, etc.).
Macs are personal computers, whether or not they come from some official IBM Personal Computer compatibility bloodline.
If you consider time zones (not every PC gamer is online at the same time), the fact that it's not the weekend, and other factors, I'd estimate the PC gaming audience is at least 100M.
Unfortunately, there's no possible way to get an exact number. There are multiple gaming PC manufacturers, not to mention how many gaming PCs are going to be built by hand. I'm part of a PC gaming community, and nearly 90% of us have a PC built by either themselves or a friend/family. https://pdxlan.net/lan-stats/
For comparison, the lifetime sales of the first Nintendo Switch would be considered a good year for iPhone sales -- six generations of phones sold >150MM units.
The attitude in the apple developer ecosystem is that apple tells you to jump, and you ask how high.
You could complain that Playstation 4 software is incompatible with Playstation 3. This is the PC gaming industry, there are higher standards for the compatibility of software that only a couple companies can ignore.