A small point (although I don't claim it militates against the central impulse of the article), is that serving analytics.js through gtag.js is obviously going to inflate the tag size unnecessarily. The latter is a unified interface for all of Google's various page snippets. Also, though not recommended, there's no reason you can't self-host GA, although practically speaking Google-hosted GA is likelier cached more often and on pretty snappy geolocated servers.