Being tax exempt certainly saves them huge amounts of money, as does all of the dirt-cheap or free labor they can command. But they are spending a lot on all of this real estate and the buildings and other improvements, and those will still require steady income in order to remain viable.
They might need to start a YouTube channel in order to generate some income. Imagine the views they would get from "Stephen Lett Reaction" videos. Maybe Tony Morris can do booze reviews? And David Splane can 'splain how overlapping generations works. They could even do "Rebuttal Rebuttal Sushi" videos breaking down Lloyd Evans's breakdowns.