If I want Man in the High Castle, I have to pay for Amazon. But if I want Ozark, I need to pay for Netflix. If I want to watch Metropolis, or The Raven, or The Maltese Falcon, they're old and not any streaming service, even if the rights are owned by a studio. Where can I find them? Yup, bittorrent.
At least piracy more-or-less forced most music to be centralised onto a single service, i.e. in many cases you can get the same songs on Spotify and Apple music. It's a shame piracy didn't force Hollywood studios to sort their out, and allow you to just go to one or two sites. Just look at what Disney are trying to do.
You are of course right: "it wasn’t an insurmountable problem after all" - it's just that studios and publishers squabble. But I'm not holding my breath on Elsevier, MacGrawHill, AddisonWesley, OUP, SUP, etc. to come up with a commerical SciHub.
You have to pay a rental fee of like three or four bucks per, just like blockbuster, but they have a much deeper pool of old movies than Netflix Streaming, I think.
That many people stop pirating as soon as something more convenient comes along does not contradict the idea that people used to pirate because it was convenient.
It was a mess of custom launchers, DRM, losing the CD/DVD or key so people would turn to piracy to access stuff they already owned.
Fast-forward a few year and most people are fine with Steam as long as it's the unified launcher for doing thing.
If there were a disruption of the world of scientific publishing that would have a parallel in entertainment I would have chosen Spotify over Steam.
Therefore, you would expect most people to opt for Netflix. (And by and large I'd expect Netflix to be more popular in mass than tormenting at this point for places where it's available.)
But what if it's not available where you live (That's inconvenient), doesn't have the content you want (That's inconvenient), or you want a file you can play offline that isn't allowed to be downloaded on the Netflix app?
Convenience wins almost every time, but not having the option to do something (be it for lack of $$$ or availability) isn't convenient so that's when more people turn to piracy.
As the end user I don't care "why" their catalog has been shrinking, I only care that something I watched last year and want to watch again is no longer available on that service.
And no, I'm not going to sign up for a dozen different services just on the off chance that one of them will have what I want to see at any given point.