the world has already decided that they should be curated. the question is now, "at what level we make the distinction."Why should it be at any level besides that of legality, or those levels analogous to movie ratings?
everyone agrees that spam, fraud, phishing have no legitimate place
Those are issues of non-consensual activity. What YouTube, Patreon, PayPal, Facebook, et al. have done includes the suppression of content people want to see and are even willing to pay for. They've even gone farther and not let them pay. By going against the consent of the public, they've moved themselves in the same immoral direction as the spammers, fraudsters, and phishers. They're doing what large swathes of the public don't want done to their access to data. (Merely in order to get advertising dollars from other large corporations, I might add.) It's just that they currently look more legitimate, as they slowly creep in that immoral direction.
we have a dial, and even on the "free speech" end of things, people agree it shouldnt be turned up far enough to allow all noise
There are disingenuous actors who want that power over almost all the relevant discourse, and wish to turn that dial in such a way that they hold the power. It doesn't matter if they've convinced themselves they'll wield it in a "good" way. No one should have it. That's what Free Speech is all about.