Some other users say that Firefox should have built-in Ablocker or ublock origin, but I recommend using Adguard as a built-in ad filtering extension, Adguard has strong ad filtering capabilities, and the Adguard browser extension is also an open source ad filtering extension, you can find the source code of this extension in Github, trustworthy, and in addition to some ad filtering features, Adguard also has other privacy features, and in general Adguard is stronger than Adblocker and ublock origin. The Brave browser has built-in ad filtering extensions, and Firefox should have them, so it can't lag behind other browsers for too long