The Cloud coincided with the early days of the smart phone. This led to a sudden, massive increase in requests to application servers. We're talking order of magnitudes larger since now, instead of people only checking Facebook while home on their computer, they could do it all the time, whenever they were bored. Humans get bored a lot.
The show Silicon Valley has a good scene about what this looks like if you're trying to keep up yourself.
YOUTUBE 0a2lv4IwZFY Antoine serves
The computing term that The Cloud helps with is _scalability_. Since you're operating in a realm where your users can grow by orders of magnitude nearly instantaneously, there's no great way to plan for that increase in scale if you own your own infrastructure. You can't just run to the corner store, and buy a bunch of servers if you need to. So if you need to scale to that size, you need to hook into somewhere that has that capacity sitting idle. That's what The Cloud provides.
But now we're nearly two decades into computers-in-our-pockets. For $100 you can pick up a raspberry pi 5 with nearly the same specs as a 2008 MacBook Pro. Antoine from the video becomes a lot more manageable when he's built from machines the size of greeting cards.
Still, the threat of going viral is always there for site reliability, and some sense of scalability is necessary. But it is not the case that everything is going to go viral all at once. So rather than keeping giant data centers running, what if people took those PCs running MUDs in their basements, and offered some extra compute, for a fee of course, to whatever hot site of the day happens to break through?
If this sounds interesting, choose your own adventure: