I have a 2014 MBA and I still can't watch YouTube videos at 1440P, unless I use 3rd party web browser such as Microsoft Edge. Microsoft Edge will play videos at 4K. But Safari, which is my main web browser, won't allow me to watch YouTube videos above 1080p60fps. Only times I use Microsoft Edge, is for testing purposes, when and if a specific website is not function properly.
Big Sur supposed to allow us to watch YouTube Videos at 4k, but I don't even have an option to watch videos at 1440P. My 10 year Dell Inspiron laptop, was able to play YouTube videos 6 years ago at 4k, and it has lower resolution than my 2014 MBA.
Only upside that I have noticed so far with Big Sur, is that YouTube videos are playing buttery smooth, with no stuttering and no buffering issues.
Big Sur supposed to allow us to watch YouTube Videos at 4k, but I don't even have an option to watch videos at 1440P. My 10 year Dell Inspiron laptop, was able to play YouTube videos 6 years ago at 4k, and it has lower resolution than my 2014 MBA.
Only upside that I have noticed so far with Big Sur, is that YouTube videos are playing buttery smooth, with no stuttering and no buffering issues.