It's perfectly fine and valid to question the pile of JS code executing in Youtube webpages, but in this specific instance the performance issues are caused by

It's perfectly fine and valid to question the pile of JS code executing in Youtube webpages, but in this specific instance the performance issues are caused by ABP/AdBlock. The issue has been acknowledged by the developers[1]. It affects only the latest version of both blockers, not previous versions, so it makes no sense to keep speculating Google is at the root of that specific issue. Out of curiosity I investigated these performance issues myself using profiling sessions[2] and the faulty code is definitely in the latest versions of these extensions. * * * [1] https://gitlab.com/adblockinc/ext/adblockplus/adblockplusui/-/issues/1576#note_1725604837 https://gitlab.com/adblockinc/ext/adblockplus/adblockplusui/... [2] https://twitter.com/gorhill/status/1746543688975581604 https://twitter.com/gorhill/status/1746543688975581604