He made it pretty clear that there wasn't a moat that he needed to forge but rather the missing the community, that's not really something that anyone could build a tool to transfer...
Indeed. And while it might seem that pointing this out is setting impossibly high standards, companies encourage communities for soley this reason. It's debatable weather the advantage of companies pushing community is worth this cost, but its something to consider.
Maybe even one of the strongest moats that exists because it doesn't feel like a cage... until it does.
Absolutely, as people who try to leave Facebook discover. It's easy to download your data from Facebook. Not so easy to keep in touch with people who have moved "keeping in touch" to Facebook groups and messenger.