They can't magic chips into existence, but leaving a major region like Germany high & dry for almost half a year sounds like planning went wrong frankly. If it were a matter of chips I would have thought on a 3+ month timescale they can steal a few from another region that has a bit of fat
That's exactly what a cloud is. It's someone else's datacenter with an API.
I mean that's what cloud is (outsourced server farm). Sure they also offer services on top, but that's mostly because they want to lock you in, and can charge more for, so it's a win win for them.
And there is no magic here, someone has to get the chips, build servers and connect them to network. And while they will often overbuild for capacity, they will never do it to a degree, where they can't run out, because that would be way to expensive and not financially viable.
I don't think any cloud will ever be able to guarantee to never run out of resources.
I agree with this, but clearly there's a disconnect between how often people expect these kinds of issues and how often they actually happen. The whole point of the cloud is you pay a premium for the added flexibility. If it turns out that flexibility isn't there when you need it then maintaining your own servers becomes a lot more attractive.
The major cloud services are expensive. This extra cost is supposed to provide for cloud services' high level of flexibility. Running out of capacity should be a rare event and treated as a high priority problem to be fixed asap.
Without the ability to rapidly and arbitrarily scale, they're just overpriced server farms.