Github is already collecting limited client-side telemetry. Open the network tab in your developer tools and you'll see a request to collector.githubapp.com on every page load that includes details like your screen resolution.
If they collect it themselves, without 3rd party script, it's more secure than including 3rd party scripts in the page, which is what Gitlab seems to want to do.
Also, who knows what else they collect about you on the backend? I find it funny that people sometimes make such a fuss about front end metrics when they could be collecting way more on the back end (especially so if it's a closed source platform like GitHub, at least with Gitlab, I can look at the back end code and see what they're collecting).
Sidebar good news for anyone reading this: Since they use a different hostname that doesn't host any operational functionality, namely collector.githubapp.com, that host is already included in most DNS blocklists.
