Thank you for this. It's not anecdotal to simply say "don't rely on platforms". Be weary of platforms that are free. They do have risks. It's important to understand those risks before thinking you've just hit a gold mine.
Relatedly, Right now, what I think we're seeing is a lack of real competition of direct substitutes. There is nothing exactly substitutable for Twitter quite in the way that products ranging from Heinz Ketchup to the Chevy Malibu face real, direct substitutes, rather than a more abstracted category substitute (i.e. Facebook is similar to Twitter, but it's not a perfect substitute). As such, switching costs are higher and it makes development for a specific platform more risky.