First thanks for working on Nebula! It's great.
Nebula seems to be about 95% there. The functionality it actually does provide once set up is really great. It's just missing the 5% that is arguably the most important for a huge number of people: a simple way to do the configuration management bits such as device enrollment, revocations, key rotations, that sort of thing.
If you are a home user, with a small network, the overhead of doing things manually is low, but you need to be patient and technical enough to read the docs and do it right initially. If you're a big enough organization I guess you can write your own tooling. But for any small shop or any non-technical home user this is not going to fly and you will bounce off it.
I don't know if the plan is to create a commercial offering for this side of the house (it would make sense...) but as far as I'm concerned, this is the only reason that Tailscale is so successful and Nebula is lesser known (despite Nebula's advantages in other ways that may be more relevant to technical users).