Many businesses do not provide phone numbers because phone conversations take a lot more manpower and time to manage. Phone, as a method of communication, is becoming less and less popular because it takes so much effort, and many people prefer to get in touch with companies through other means.
Large tech companies arguably have millions of users everyday, and being able to pick up phone calls daily just does not seem viable. Especially when callers can get emotional, phone calls can become extremely slow and inefficient. As an alternative, these companies look to emailing, messaging and creating detailed FAQ sections to provide the customer service that is needed.