>Part of that, of course, will be because YouTube forces video codecs that may not have hardware acceleration on your platform Codecs supported by Youtube (VP9

>Part of that, of course, will be because YouTube forces video codecs that may not have hardware acceleration on your platform Codecs supported by Youtube (VP9 and x264) have had GPU HW acceleration support on most PCs and laptops sold in the last 8-10 years or longer, just that browsers on Linux never enabled it out of the box because of the wild number of variable on the graphics HW acceleration stack (Mesa, Wayland, VA-API, Nvidia, FOSS/proprietary driver, etc) made it impossible to guarantee it would actually work out of the box, so it defaulted to SW, and HW acceleration was left for the user to tinker figure out on his own, unlike on Windows where you never even had to think about it, it was always working the moment you installed the bowser.