It sounds like this will be your fist time running Linux. In that case I would recommend against using CachyOS or Arch. Those distros are meant for experienced users that are willing to solve problems on their. In the words of the Arch wiki:

Whereas many GNU/Linux distributions attempt to be more user-friendly, Arch Linux has always been, and shall always remain user-centric. The distribution is intended to fill the needs of those contributing to it, rather than trying to appeal to as many users as possible. It is targeted at the proficient GNU/Linux user, or anyone with a do-it-yourself attitude who is willing to read the documentation, and solve their own problems.

In general, you can have a good gaming experience on almost any distro. The main limitation is probably running brand-new hardware, which can be a bit difficult on some of the slower distros (Debian, Ubuntu LTS, Mint, …). There are only very minor performance differences between distros.

If you’re a new user that wants to use a fast-moving distro with many options for customization, I’d recommend Fedora (e.g. Fedora KDE).

I think it is a disaster and that the lack of long-term API/ABI stability (outside of the kernel) is one of the biggest things holding commercial software on Linux back. It’s much less of an issue for FOSS software, which can easily be recompiled or adapted. However, a lot of people (and companies) want to run proprietary software (e.g. games) on Linux.

This type of breakage causes problems for both developers and users. If you develop software for Linux you need to continously maintain it in order to ensure that it keeps working. And as a user it can mean that software which was working perfectly suddenly no longer works after an upgrade. For example, you may just no longer be able to play any of your older Linux games. If they were built for Windows you can still run them after 20 years, and they probably even work on Linux too.