To be pedantic, scaling by itself isn't that difficult.
Scaling cost-effectively is.
Scaling cost-effectively is.
(Just like sending a human to Alpha Centauri is hard, even if you had unlimited funds.)
If Netflix built out more slower servers, that would be acceptable scaling. I don't see any plausible scenario where that becomes too difficult. Even if they had billions of subscribers.
Eg enriching a tiny bit of uranium is 'relatively' easy. Enriching enough of the stuff to build an atomic bomb is a question of scaling. And, yes, in principle you can just use more and more centrifuges etc.
Humanity has already built some small infrastructure off-earth, like the ISS or satellite networks. Also various unmanned probes that toiled away for years in space and on Mars.
Building a habitat big enough to plausibly keep humans alive for the decades or more it would take to get to the Alpha Centauri would involve enormous scaling efforts. And that's not even touching on propulsion, yet.
However, yes, grand feats require more than just scaling.
But we're not scaling for scaling's sake. We're scaling with the number of customers.
If it was profitable to enrich some milligrams by hand, then you'd be able to get more scientists and engineers and better equipment and automate some parts and make even more profit. If you go the centrifuge route, it's not because you had to do the harder methods, it's because it's massively cheaper per gram of product.
Such a scenario is very different from "we can't do it at all, and we need to build complex infrastructure just to make it possible".
* after a certain scale
What I've read they burned a lot of money and hat large problems scaling nevertheless. Which I don't find too surprising, not because they are unable, but because it isn't easy to scale.
From my experience and from what I read scaling people roughly a power of ten is a larger change in an organisation and therefor likely a challenge. For _any_ technical process the boundaries might not be strictly a power of ten but i would say that scaling a power of a hundred is a challenge if this value is not already reached on any process in your organisation.
Scaling to - say - Paramount+ size should not be difficult if you're willing to pay AWS / Azure / GCP 10-100x what it would cost to serve it yourself (which in many cases actually makes sense).
It's possible at Netflix's size, they couldn't just run on AWS anymore. Though, given enough lead time and a realistic growth curve - I'm sure it's feasible.
Obviously scaling manufacturing is not a solved problem like (realistically) scaling network and compute usage.