google makes products, they mostly suck at making platforms, and their most notable platform (android) was purchased, though one can argue gsuite/workspace as a platform, but one might also argue that its more just an amalgamation of projects.
One can see this from the failure of google+ (and killing off beloved apps, like reader on its altar, when I would argue if they are thinking platform, the idea is to make any app insert data into the platform, you don't want to push away users, you want to get them using the platform with them even knowing it).
Or their disjointed messaging strategy for many years (which might not even matter, they seemingly have given up on it?). It shouldn't matter what messaging app someone uses, let it use a common platform. Spend the money on figuring out how to make them use a common platform, because killing their app just pushes them away and you are not guaranteed that they will move to your new app vs something else. Moving their old app to your new platform, again, keeps them as users, increases the value of the platform (as more users are inserting dfata into it) which makes it more valuable to others to do the same. One might have different apps geared towards differ things (someone might be happy with just text messaging, another might want video and text messaging, but if you kill the first guy's app and expect him to move, he might just as quickly move to whatsapp or something else).