Earlier, after the official launch of iOS 14, YouTube suddenly loaded Safari into YouTube and enabled the "Picture-in-Picture" function to prohibit it. However, YouTube Premium users can use it. Many people think that YouTube is banning the iOS 14 Picture-in-Picture function for profit.
However, since the official launch of iOS 14.0.1, suddenly even users without YouTube Premium can use the PIP feature again! And it can be used without changing Safari to Desktop version, which is very convenient.