Earlier quoted context omitted.
Come on, in the 90s and early 00s, volunteers ran and managed IRC networks scaling up to hundreds of thousands of users. This was back when hardware and bandwidth were much weaker and 100x more expensive. It's really not that hard.
Yes, volunteers ran these things. How many? Because you're going to need to have paid employees rather than volunteers running your servers. Is it going to be more reliable and cost effective than just paying a third party to run a service for you?
I can set you up a resillient architecture and 3 services (communication, documentation, filesharing) in less than two weeks (let's say two weeks and a half because security concerns/limitations and all that stuff). Add one week and you will have mail server, VOIP communication, log conservation and monitoring, backup images on CEPH, vnc service for "easy" maintainance and a small documentation explaining the few action needed to maintain the monster for two years. Initial cost for a company: 15 to 25k$, + 1 hour and ~100$ a month.