YouTube will likely always carry controversial content even if that's just from an archival point of view (digital record). The challenge for Creators is monetising in light of the new policies that essentially kibosh anything gaining traction regardless of the materials merits (the exception to this would be already established actors with large user-bases... but even then they are solely dependent on YouTubes 'subscription' algorithms not neutering notifications).
Of the few alternatives that have sprung up, few are likely to gain significant/sufficient traction, look at Vimeo as an example, it's been around for a little longer (2004 vs. 2005) and still hasn't anywhere near YouTubes reach (c.170 million
vs. 1 billion users, 100 million vs. 1 billion monthly views
etc.). YouTube, as they say, is
the battlefield, it has the greatest reach because its where everyone is. That'll take some doing to topple in any meaningful way - those leaving and going elsewhere may be able to 'earn' from the efforts, but in doing so they're likely tapping the same relatively small pool of like minded people for views and income. That typically doesn't last, at least not unless these new alternatives can somehow catch mainstream attention whilst bypassing the 'alt' stigma that same mainstream is busy painting everyone with. And this is notwithstanding the Googlopoly (Googleopoly), the depths of their pockets and their political reach.