Unix convention to hide. .Files hidden from ls unless -a used but cd .config/ works fine. It matched the use of . For "this dir" and .. for "parent dir" also hidden by default. It was in v7 on a pdp11, my first experience of Unix in 1980. Probably pre-dated that.
Oh sure. I started with v6 on a pdp-10 in 1979. And the leading dot is ingrained in my brain.
But what I'm wondering about is the idea of associating (for example) "myfile.xyz" and ".myfile.xyz". I've never heard of this as a convention for associating metadata.
