Currently the known way to have a mobile number is to buy SIM card physical chip and insert it into your mobile phone but this causes alot of troubles to privacy/security e.g:
Active SIM cards (inserted into working phone) can track your physical location 24/7.
It can be used as a backdoor to sophisticated malware like pegasus.
Privacy concerns when registering into Signal or Telegram or 2FA… or any service asking to use a real mobile number.
To get these issues fixed is to not use sim card at the first place and get a phone number working through xmpp/jabber network, This service is available by https://jmp.chat/ and you can use xmpp client to communicate and use the number.
I have tested the service and i find it really worthy like the fast registration, you can register with signal,telegram readily after activation (reliable) , active support , you can pay using cryptocurrency.
I would like to add this service to the wiki as a method to register into services which requires mobile number without revealing your identity/real mobile number or as one of the methods to avoid using sim cards or even the need to use a mobile phone.