With today’s smartphones, you usually get a minimal set of functionalities out of the box and go through installing diverse applications for your different needs. Usually those applications are proprietary and are designed around their own unethical business model; hence they compete against each other for your attention and have their own set of features to be used within the scope of the application only.
This can lead to a lot of redundancy and confusion in terms of functionality. A particularly blatant case is communication applications, where we see each application handling their own contacts logic, their own locked down and isolated protocol, and where a ton of applications will implement the same things for the same purpose (making calls and sending messages), with the focus typically being the flashiest application to attract and retain the most users.
François Téchené (purism): Design report #4: symbiotic applications