Self hosting means downloading the source of a script (e.g., jQuery), and hosting on the servers your site/app serve from. So I assume that GPs site is hosted on AWS and this may make more sense?

Else yes, a bit confusing.

What? The whole infra runs on us-west-2 and there are no 3rd party resources loaded from elsewhere.

You expect us to run servers in our bedrooms to count as self hosting?