I installed CachyOS on my MacBook 16,1, and it feels much faster than with macOS, but the D side is still hot though.

No thank you. They can sit in a museum 30 years from now. Today, they are still amazing and productive machines (once you get macOS off them).

Many (most?) Intel Macs still receive microcode updates, Mesa support and recent kernel changes.

The only obsolete part is macOS, which is removable.