Macbook pro 13" 2015 not supporting 4K youtube in safari ?

Hey, so basically I recently updated to Big Sur (macbook pro 13 inch early 2015), but I can't find 4k quality in youtube videos (in the videos that provide it), the question is, am I doing something wrong or there is a list of devices that support 4k and my mac just doesn't support it?
Macbook pro 13" 2015 not supporting 4K youtube in safari ?
 
 
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