How is the clone going to be financed? Are you going to sell ads on it? If so, who is handling that? ... and making sure that the advertisements don't show up where the advertisers don't want them to.
Who is going to handle the inevitable legal takedowns for copyrighted works, trademark infringements, or things that may be illegal in some country? Is it going to serve porn in the Apple App Store?
Standing up a clone is easy. Keeping it up with a healthy community there (even if you are able to grab all of the existing users of an app) and being able to afford to keep it running - that's the hard part.
Voat would be an example of a social media site that was spun up without VC interest (it started up as a hobby project from a college student as an alternative to reddit in part because of moderators).
And so I return to my question: if it is viable to do without VC funding and the demands of revenue growth - why aren't there more of them out there?