IMO this diagnosis is still one level away from a more fundamental truism, which is that people don't want to pay anything for digital goods. Running servers can and has been massively simplified over the last couple decades, and I don't see any inherent technical barrier preventing it from being as simple as registering for an account on FB (i.e. anyone can do it). The deeper problem is the lack of willingness to pay (directly) for anything online.

The reason for this is complex, with lots of unclear cause and effect dynamics (e.g. did our unwillingness to pay push the ecosystem to gravitate towards ad-based revenue models, or the other way around?). The inevitable race to the bottom between competitors, under the massive incentive for platforms to centralize/consolidate (if you charged any amount for your service I can always under-price and out-compete you) is likely a major contributor. We do not exhibit such reservations against payment for anything physical, probably because of the innate sense we have that anything in physical reality should have a cost, yet not so in the digital world.