Good points you're making. I think you could think about the answer like this:

We're on Steemit for a reason; hopefully good content will be valued accordingly and the rightfull owners of the content will be therefore incentivized to continue providing quality content. The question is wether scammers and copycats can take the content from Steemit and monitize it elsewhere. I'm sure they can but I think they wouldn't receive as much value as on Steemit.
Crypto money is not going away, in fact the opposite is true; crypto has solved the internet money problem. It has many benefits; not regulated, no debt or interest jacking up the price, not taxed. I foresee a future where everything is going to be incentivized through crypto money because it works so well. Take open source software development. People will always want to do what they like. Artist are going to make art etc. But in the end the actions count. Nice words are almost for free but upvotes will actually mean something.

Big projects like films and music will have to find long term monetization opportunities to be a viable source of income. People will tend to flock there where there is true value. And because Steemit is a social platform it makes most sense that long term projects like film and music get promoted on Steemit. There just needs to be a mechanism to get those upvotes flowing to the people behind the film or music project.