IMHO the
worst form of private debt in our present economy is personal private debt. We are in a severely demand constrained economy, and personal private debt is really what's weighing the economy down and soaking up consumer demand. Also unlike corporations individuals cannot do debt/equity swaps or raise money by issuing shares in themselves, so personal private debt is harder to renegotiate or reorganize into a more manageable form.
Corporate private debt is maybe the next worst, but as I said corporations have many more tools for dealing with it especially if they are otherwise healthy. There's a huge market out there for equity in healthy and especially growing companies.
I have heard the interesting view that government debt and private debt are not even the same thing.
When you think about it: the government prints its own money (or authorizes the entity that does, e.g. the Fed). How can you truly owe a debt in your own sovereign (fiat) currency? How is debt still a meaningful concept there?
It seems to me (and IANAE) that government debt is more like equity in the nation. Owning a bond is like owning stock in the USA, but with the caveat that you are forced to resell this stock at its maturity date. Maybe something closer to a weird kind of convertible note.