About the operating cost, I feel like it is a matter of perspective as well.
When someone runs their own Plex server for example, they can easily justify it as one-time costs, they take responsibility for certain things, certain costs are “indirect” like power/bandwidth, and they do not see the value of their own time.
But if you wanted to do something similar for a larger user base, now the users see one big number that includes the hours you spend, “infrequent” hardware failures becoming a weekly occurrence, and you now taking on risks like copyright.
I would be willing to bet that many services are cheaper to rent than self host if you include all the hidden costs and time and other resources spent.