Earlier quoted context omitted.
They absolutely can play popular music. They just don't want to pay for it. All popular YouTubers and streamers are businesses which is a part that is often forgotten. They are all acting like they are friends with their viewers but in reality they are businesses just like a car wash, restaurant, plumber, etc.
One underestimated part of the gig economy is that eventually everyone will be a business, and eventually they will be on the clock all the time. I guess that will be the end of music. Do Uber drivers have to pay a license to have the radio on in the car?
In the UK, yes, https://pplprs.co.uk/wp-content/uploads/PRS-for-Music-Tariff...