How soon will phones go away?

My world is changing. I was filling out a computer form today that insisted on my phone number before I could proceed. I do not use my phone. As I sit here typing, I am still trying to remember the last time I talked to someone on it. I work internationally, and my voice calls almost always are completed with something other than the phone system. Viber, Whatsapp, Kik, Messenger, whatever. Something asynchronous whenever possible. I have a hand held computer, not a phone.

I still have a phone number, but I do not know for how long. It has almost no utility for me. My landline disappeared decades ago. My fax line disappeared about the same time. I shake my head and grimace, then take a picture with my handheld computer with an App whenever someone insists on a fax. I do not want to pay for something I do not use. The only people who ever call me are people trying to sell me something that I do not want. Today I realized that my phone number will disappear soon. A year maybe, if that.

So what then? What do I do when a website refuses to proceed unless I enter a phone number? Just make one up? A 555-BR-5479 kind of thing?

Any website I am involved in designing from this date forward will have a phone number as optional whenever someone is asked to enter their contact data.