[zeroer]

I don't have a default number.

You can see why I might think that forcing phone number to equal identify might be a bad idea.

I understand that I'm an unusual case, but I'm sure plenty of other people go through something similar this every couple years if and when they switch phone numbers or providers or move.

[etatoby]

I have had the same mobile number for the past 20 years, throughout dozens of different phones and operators. This is very typical where I live (Southern Europe) where, in fact, WhatsApp is very popular.

Question: how do people you haven't been in contact with manage to find you, if you change your number every 2 years?

[zeroer]

In the past three years, I haven't spent more than 60 cumulative days in a single country. Keeping a single phone number is a nonstarter for me.

People contact me via email. Apple's iMessage is the only chat client I've been able to use effectively, because they tie identity to email, not phone number.