Currently the main attack facing Firefox is coming from advertising companies such as YouTube. It’s crazy to think that some software engineers might actually intentionally degrade user experience on non-Google browsers or for people using adblockers. The mentality here is pretty disturbing: it’s almost like punishing users for making the choice to browse the web without ads, or without the surveillance mechanisms th…
about youtube being totally unusable on firefox: is it just youtube/google being evil as is customary or also firefox having loads of memory leaks, as its usual too? (plenty of mem leak bugs with video/audio reported over the years, many very recent and still open)
The only problem I really remember is at one point Firefox having issues under linux when NVIDIA was swapping their main driver over to the "open-sourced" version, there was some performance issues with decoding, not unusable - but it was resolved within a week.
But, this is just my experience.