We are slowly drifting into a technological nightmare.
It is becoming increasingly difficult to operate in society without a mobile phone. Important appointments often happen by phone. Verification of your identity (eg: SMS verification codes) can require a phone number. Organizations expect to be able to get hold of you any time of the day, wherever you are physically. Organizations also often block caller ID making it difficult to distinguish them from phone spam.
Many important services are drifting towards requiring a smart phone. For example requiring a mobile app for identity verification, even when using a desktop application. These applications are distributed via platform app stores. These apps are increasingly refusing to be installed on rooted or bootloader-unlocked devices. This effectively means people are required to have a platform account in order to use these applications. As more functionality is moved from physical interactions to interactions via mobile applications, services are cutting staff in physical locations, making it more time consuming to do things the "manual way".
Example: In The Netherlands there is a government identification system called "DigiD". Some DigiD secures serviced can be verified using SMS, but due to security concerns some of the more sensitive services (healthcare) require verification via the DigiD app. This app requires activation with either a Dutch passport, or a Dutch drivers license. Many expats in The Netherlands have neither. Even if you do have a drivers license, the application will not install on a bootloader-unlocked phone which means Android users must have a Google account (not taking into account hacks to get around this). It is not an impossible future to imagine that in order to interact with Dutch government services online you are required to have a smart phone with an account from either Google or Apple.
Many companies effectively require their employees to own a smart phone. There may even be a "soft" expectation that emails and messages are responded to when the employee is not on the clock (not just after hours, but for example holidays or mental health days when other employees might not be aware the person is not working that day). Some companies require people install software on smart phones in order to access the corporate network (fair enough), but put up barriers to employees getting work phones (not fair).
WhatsApp has become a communication medium
Where are we going:
Let's look at digital communication methods from the past:
Email is an open protocol. Regardless of the difficulty, you could run your own mail server on your own domain and still participate in email communication. Big providers dominate, but there are too many participating for any one to make a single walled garden. What might happen is the big providers make a ring of walled gardens and nudge out the rest. However this would be very difficult as there are still many small offices running their private mailservers.
Email works because most of the innovation has slowed and is standardized. So far no single big provider has come along with the next big killer email feature and captured the market to form a walled garden. I think this would be almost impossible at this point. Like it or not email is here to stay, and it's one of our best hopes for open digital communication protocols.
SMS is an open protocol. It works between mobile companies. You are not required to have a Vodafone account in order to SMS another Vodafone user.
Obviously calling is an open protocol. Someone on T-Mobile can call someone on Vodafone.
These pre-WhatsApp protocols are open for the most part. However they didn't get widespread consumer adoption before WhatsApp blew them away. WhatsApp is now a walled garden. When WhatsApp had an outage in [year] we discovered many people working in governments were relying on WhatsApp to communicate with each other.
There are many technical fixes for the situation, but the problem is not technical - it is social. The general population is simply not technically savvy, and likely will never be. If you care about this stuff but acknowledge that you still need access to digital services, the future will likely be that you have one mobile phone that has an account with a big provider that you distrust, and another phone that you trust.