Yeah, one of the biggest examples being the HTML 5 video push and Chrome’s claims around H.264: Google promised they were going all in on WebM and would remove support soon, but never did. That meant that Firefox users got more errors outright but also that for years even sites like YouTube would leave Firefox using 100% CPU with your laptop fans on high doing software WebM while Chrome users got hardware accelerated H.264. That became moot after Mozilla and Cisco struck that deal and video hardware acceleration for other formats shipped but there was a multi-year period where Firefox suffered badly in comparison to other browsers.