Probably the only reason you might switch is for something like CachyOS that probably has the similar problems you get with Arch but with a more custom kernel with their own tweaks/configurations to speed things up and provide newer hardware support in general.
Either something like that, or a want to switch and try something either new and/or more/less advanced... if there's even any distro more user friendly than Mint.
Otherwise, the only other reason I could see for leaving would be if you for some reason don't like how Mint is developing/being developed.