For me, email has much more credibility than phone numbers. The email market has worldwide competition, phone providers compete at a local level only. You can

For me, email has much more credibility than phone numbers. The email market has worldwide competition, phone providers compete at a local level only. You can choose from thousands of different email providers, while phone provider choices for any given person are ~5. The effective 'god' of domain names is IANA, which, while imperfect is more trustworthy than the 'gods' of phone numbers: local governments and telcos.