Typing a complaint is work. You have to organise the problem into sentences before you can even start, which is exactly the moment a frustrated person gives up and calls instead, or gives up entirely and tells someone else about it. Voice removes that step. It is why WhatsApp voice notes took over ordinary conversation in most of the world while support channels stayed stubbornly text-first. It matters more in some places than others. Customers who find typing slow, customers on the move, customers more fluent speaking a language than writing it, older customers who never adopted messaging conventions. In each case the choice is not between voice and text. It is between voice and not getting help at all.