This is 13 lines of Bash plus GPG which is available ~everywhere and a pretty lowish level Linux dependency. SOPS is +20KLOC of Go with support for cloud KMS etc etc. I think you got your mystery meat analogy backwards.
I’ve used a Linux desktop for my entire adult life, and I’m pretty sure GPG has never been bundled directly with my environment. I used to install it directly, but I haven’t needed that in years either since everything I needed GPG for (= git) supports SSH signing instead.
Perl is horrible, but for one-liners it's strictly less horrible than either sed or awk, which people still use because they are less horrible than pure Bourne shell for some common tasks.
(I also wouldn’t call GPG a low level dependency.)