This is an absolutely braindead lazy take.
The same professional journalists who've worked at these big media corporations have used the substack platform to open up sites in droves so they can focus on more niche topics, or just escape the censorship of owners and advertisers.
If you think that legitimate news can only come from a company owned by billionaires, then you're wrong.
What subject, and was it time limited? If there was any chance of not finishing in time I'd probably leave those until last.