A burner phone is a device, it doesn't come with a phone number. Phone numbers are all real-identity-tied, so what they really mean is _identity verification_ through phone number. Everyone on HN knows the downsides of that, but there's clear upsides too. It prevents most of the digital "This is why we can't have nice things". The US is on the path towards the worst of both worlds, services still require you to do identity verification but it involves sending your government ID and face video to Thiel-affiliated Persona.