I do think the idea behind snap isn't all about pushing the Linux platform as such forward, but to specifically gain a market advantage to Ubuntu.
Why else is finding documentation for changing the default store so difficult? And I don't think you can even have multiple "repositories" there--quite unlike all other Linux packaging systems out there. (Corrections welcome!)
As I understand it, these kind of applications depend on being able to perform activities in the background, which is highly limited in iOS for battery efficiency reasons--and maybe for privacy.
Many years ago I was working on a project that shared connectivity details over wifi/bt, and iOS was troublesome also due to the application not being aware of the local bluetooth address.
Possibly similar issues impact other mesh networking applications on the platform.