An interesting tidbit from the podcast from the Google folks was that Gary Illyes from Google said a heck of a lot of sites are already using the rel=sponsored link attribute. He said one million sites are already using the rel=sponsored link attribute.
https://www.seroundtable.com/one-million-sites-using-google-rel-sponsored-29626.html
https://www.seroundtable.com/one-million-sites-using-google-rel-sponsored-29626.html