One thing I'm wondering (and might've missed) is: is their an equivalent of the Webfonts API for regular stylesheets and scripts?

Otherwise using a mix of wp_enqueue_styles() and _scripts() and APIs doesn't really make for a consistent programming flow, IMO.

For those of you who are looking for an easy way to host Google Fonts locally; give OMGF a try. It's available directly from the WP.org repository: https://wordpress.org/plugins/host-webfonts-local/