Note on (a): some will argue a difference between Google advertising Chrome on Google’s property (something they could do when bootstrapping Chrome) and advertising Chrome on other people’s property (something they could not do). But here, Windows and Edge are Microsoft’s property, like it or not.
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.