I have no metrics but there is a lot (if not most of) sites with similar issues.

A simple site of lyrics, or newspapers that start videos automatically. Github was worse, now at least opens a bit more faster, but still very poorer than, example, codeberg. Sites are sites, most want to do fancy things more than to simply let user read its contents.

Would be nice a site that could track it to put some shame. By now, the better sites are just like HN, Wikipedia... unobstrusive and fast even without cache.