This deep-dive ended up improving the @eleventy docs on our Quick Start guides:

1️⃣ https://www.11ty.dev/#quick-start
2️⃣ https://www.11ty.dev/docs/#step-4-create-some-templates

And we now have a cross-platform command to create files to make this easier for folks:

3️⃣ https://github.com/11ty/create

Thanks @sarajw for the push!