I started several years ago with the YouTube Premium family plan. It gave me:
YouTube Originals
YouTube Music
No ads
Background playing
My kids are fine with it. It saves me and them a Spotify subscription. Having YouTube Originals disappear somewhat, lessened the value for me. Once the kids are not under my roof anymore, I’ll have to rethink this subscription plan. But that will be in eight years, or so. In that time so much will change, it’s not even worth thinking about it.