This issue was previously discussed in Using the bare name of a generic type within itself.
Money quote from @Douglas_Gregor:
It seemed like a nice convenience when I cargo-culture it years ago (we didn’t have the general Self at the time). I’d love to phase this out of the language.
— https://forums.swift.org/t/using-the-bare-name-of-a-generic-type-within-itself/24778/26