The moat is that it has users, not that it’s impossible to clone. Though developers vastly underestimate the difficulty in cloning something as well. As someon

The moat is that it has users, not that it’s impossible to clone. Though developers vastly underestimate the difficulty in cloning something as well. As someone who thought it would be trivial to clone phpbb, it’s a lot of work to reach just feature parity. Your clone isn’t even going to have users to motivate you beyond the first 0.1% of the work.