This isn't about advertising, it's about not following system defaults.
On my iphone the GMail app seems to frequently "forget" that Safari exists and I'm prompted to install Chrome when I tap a link.
https://i.redd.it/tg2yj98o5ao51.jpg (Obtenir means Get/Install).
It seems (?) to be a bug but it makes me wonder how widespread the bug is, how often it's triggered. But that is very not cool. Thanks for the screenshot.