> but no real mid-sized or bigger company is going to be using Whatsapp or any other consumer messaging service for their critical or non-critical business communications.

Before the Russian/Ukraine war, I worked for a US company that did business operations on Russian cloud providers - one (very major one I don't want to name here publicly) had their main support in some sketchy all-russian telegram channel that I only could access via my personal device. You'd type your issue in english, get a bunch of russian responses, and then sometimes hours/days later your issue would mysteriously vanish.