To prove your point... https://www.sitepoint.com/reddit-clone-react-firebase/

Yes, it's basically just a scaffold, but something like this could be iterated on. The challenges are around infrastructure and funding to function at scale.

I would personally rather see something that improves on the problems Reddit solves, but tries something completely new. Cloning a product is so uninteresting.

Yes and no, the tech of a forum is not interesting, but fostering a healthy community that generates value is an eternally novel problem as every success has been the result of good timing more than anything else.

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.

I mean more like “going head to head against Microsoft in office productivity” type moat, vs “this is hard for a solo dev with no budget” type moat.

Reddit has no real moat.