Not only crypto but any other thing you want to use your phone number for registration. Many registrations demand the use of a phone number, however if using an email address is an option, it should be chosen over using a phone number.
I recall receiving a call lately from some scammers who had registered a new WhatsApp account using my phone number and asked me to provide a code that they would give me while we spoke. They accurately identified the organization I am a member of when they mentioned there would be an online meeting, and that I would need to provide them with that code in order to participate.
I was given the code, but all I did was ask them a question that they were unable to answer, and as they realized I had identified them, they hung up. I'm affirmative they obtained my number during an earlier registration process in which I used my phone number. They were able to compromise the information there and are now searching for victims to fall into their trap.