Questions of "how should a company behave?" can only be answered by one's feelings, and feelings require emotions to be formed. There are no rules of business encoded into the universe. Business itself is merely a human construct.

> At end the end of the day, if I need to make a call to the old country and various apps don't work for one reason or another

The modern phone system is built on apps, so if apps are not working for one reason or another the app you call a phone isn't going to work anyway. Long gone are the days of an operator physically connecting copper wires between two locations. The phone system you seem to be imagining no longer exists outside of museums.

> Papyrus is older than telegraph and yet it is still used to deliver important messages

And like I said in another comment, if you used papyrus to request support from your telecom operator, I expect you would receive even worse support than by phone. It's not where they are going to focus their energy because papyrus isn't where the community of customers live. I imagine they would put in some effort to accommodate you, but with only so much time in the day it will pale in comparison to where they put their focus.

> unless you have some evidence to prove, calls are indeed a fringe channel

Like I said, it depends on the business. The phone is unquestionably the primary channel of communication for some businesses when the community of customers primarily live by phone. Other businesses, particularly those close to government, do rely on papyrus as their primary channel of communication. And other businesses see physical presence as their primary channel. Going back to the restaurant, you're going to receive better service walking in the door than you will by phone. No doubt there will be a best effort to provide good service over the phone as well, but the customer who walks in the door is going to get the "A team".

The business of which we speak here is mostly in the business of connecting one's pocket computer to social media, so social media is quite expectedly where the community primarily lives. That doesn't mean they won't put a best effort into other communication channels, but if you want the "A team", you will reasonably go where the people are. Same as with every business.