The phone number is associated with the person with a contract that has all the info to find you IRL. Certain people can physically find you by knowing your phone number. And it is how we connect to the Internet on the first place. With the exception of Whatsapp and a few others, Internet accounts don't use phone numbers to connect people, they just use it for auth and then keep it (relatively) private.
Why not Telegram though? Most people have it and you can interact with them by knowing just their username. Telegram doesn't sell your data in any way and you can start e2e encrypted chats with limited functionality to share sensitive information.
Telegram has always been the perfect middleground for me.
I guess your last resort is email, everyone has it and once it was a very common way to keep in contact. FYI Delta Chat is an instant messaging app that just use emails under the hood.
About Instagram you are right if the person actually share personal information but if I had an Instagram account I would still feel safer sharing that than my phone number.
@post Are you suggesting I should ask the email account to keep in contact when I flirt?
I shall try that next time, if anything I can get a few laughs out of it.
@post Telegram does not work out simply because most of the people don't have telegram where I live. When I meet someone new I need to have a way to keep in contact with them.
Everyone has a phone number, that is the advantage of using the phone number. Moreover, the phone number allows you to make phone calls.
While surely the phone number is associated with a contract that has all the information about you, you'd need that contract to get to know that information.
I fail to understand why someone who doesn't know you should be interested in knowing where you are. If these things are a concern, then I'd imagine you would not wish to share any information about you. Thus, Instagram really doesn't make sense as it contains a lot of details about your personal life.
Let's put it this way: if I met a business competitor, I'd rather share my phone number with him rather than my Instagram, even though through my phone number he may gain some information about my routine.