YouTube Music is starting to become audio-only for free listeners as it will no longer be able to play videos for the users who have not subscribed to YouTube Premium. The update will initially be available to YouTube Music users in Canada starting next month.

source https://gadgets.ndtv.com/entertainment/news/youtube-music-free-tier-audio-only-listeners-users-videos-premium-update-2582748#rss-gadgets-all