Netflix already doesn't have that big of a library, and it's been steadily shrinking. But if it comes down to it, i'm willing to pay for $10/mo to netflix purely for their original content. I'd also pay for HBO Now if they would let me (I'm in canada). I don't think there's any other company putting out enough quality first-party content that i'd be willing to pay a monthly fee for their service. maybe a couple bucks here and there for a one-off movie rental, but if i have to think about money before i watch something - even a completely insignificant amount - i'm probably going to find other options.

And as you say, there's always piracy to fill the gaps in any streaming catalogue.