Line messaging app that is popular in Japan has had adverts for years. They aren't very intrusive. I am fine with it. They also sell "stickers" (elaborate emojis) as an alternative revenue stream. They are surprisingly popular amoung all ages. If WhatsApp takes a page from their book, I will be fine with it. I have never paid a penny to FaceBook/Meta for running this amazing, free service. Nothing is free in this world.