I've never seen one on mine - behind a pihole though.

It does push paid content (as in rented/purchased movies/tv shows); I don't consider these to be adverts, per se, but obviously you might.

only in certain countries it seems. When I'm VPNd into the US for an extended period of times ads pop up, but when I disable it, they relatively quickly go away.

This seems to be changing; I'm getting the two rows with shows I don't care about and cannot be disabled in Europe too.

Changing the default launcher allows you to solve this.