Can I reduce how often CachyOS updates packages?

There isn’t really a supported setting in CachyOS that changes Arch packages to update only at major versions. Arch expects users to keep the whole system reasonably current, including core libraries and sometimes the kernel. Selectively holding back individual packages can work temporarily, but doing it broadly may eventually break dependencies.

You don’t necessarily need to change anything if the system is working well. Many rolling-release users update once a day or every few days and check the package news for major changes. If you don’t need the newest software, though, a stable-release distribution will probably be a better fit than trying to force CachyOS into that role.

CachyOS is based on Arch, so frequent updates are part of its rolling-release design. The official repositories generally contain stable upstream releases rather than random beta versions, although packages from the AUR can be less predictable. Holding updates back for too long on an Arch-based system can create dependency problems, so it’s usually better to update regularly or choose a distribution with a slower release model.

If you mainly want a dependable desktop that doesn’t update constantly, switching distributions is probably the simplest solution. Debian Stable, Linux Mint, Ubuntu LTS, Fedora, or openSUSE Leap provide slower and more predictable update schedules. openSUSE Slowroll is another option if you still want a rolling-style system with a more conservative pace.