The former Vice crew (404, Remap, probably others) have talked about this in their various podcasts and blog posts and so forth:
My take is that there are two big, but linked, problems:
The first is... there is a reason all these news media outlets are shuttering. People don't want to read. They also don't want to watch a documentary that isn't over-dramatized trash. And any form of monetization model mostly just antagonizes the audience who were never going to consume it in the first place but will GLADLY derail every single discussion to say how much they hate a paywall. So you become VERY dependent on your hardcore subscribers and that is an incredibly dangerous tightrope to walk. Do you prioritize your coverage based off what your patrons (because that is what they are) would want? Do you NOT cover something because it might make subscriptions go down? What do you drink when you realize you are literally the person who fired you a year back?
And the other is that legal representation costs a lot of money. Last Week Tonight have covered SLAPP Suits a few times over the years but that is also the reality of it. Any form of investigative journalism pretty much guarantees you are getting, at the very least, a C&D. If not a full blown lawsuit. A good lawyer can make the vast majority go away but... a good lawyer costs money.
The former Vice crew were pretty much all in a special case. 404 came out of Motherboard which was pretty much one of the most trusted and respected "tech" news sites out there. Aftermath has some of the Motherboard crew and but also is basically a who's who of games media as a whole (arguably everyone who was keeping Kotaku alive). And Remap is mostly the people who were at Waypoint until Vice realized they were still getting paid and that audience is one of the most rabid and faithful out there when it comes to subscribing to content we love.
Whereas most outlets actively try to prevent people from getting enough popularity/notoriety that they could get their own funding for a new start. Like... think about who the big names in traditional news are? MAYBE you remember whatsherface's name from PBS? But it is almost entirely going to be the anchors/commentators like Anderson Cooper because they are the ones you see night after night and they are the ones who present the stories written by the "normal" journalists. And zero shade to Mr Cooper, but that is very much intentional. Because if some third party wanted to pay him to spin up a new outlet? That's great, but they ALSO need to hire like three or four more journalists to have anything for him to say.
As opposed to a Jason Schreier who, with sufficient lawyers and a contracted editor, can be more or less a one person show.