Mathematics is not typically considered (by mathematicians) to be a solo sport
I agree and disagree with this statement. I feel that when I'm doing mathematics, then I tend to work best by myself. But if you'll pardon the slightly vague sentence, actually doing mathematics is only a part of doing mathematics. To be a little clearer, when I'm actually trying to prove or devise or learn something, I prefer to do it by myself and work at my own pace. But when trying to figure out what to prove, or what conditions the new thing should satisfy, or how what I've just learnt fits in with the rest of mathematics, or what to learn next, then I need to interact with others.
The difficulties of doing this is pretty much what the nLab is set-up to solve. When working on the nLab, I'm both working alone (and thus at my own pace) and in a group. I like to think of it as like working in a library - most of the time, one can work at ones own pace, but there are lots of other people nearby working as well and that helps. Being surrounded by other people clearly working hard encourages me to work hard as well, and there are experts nearby in case I get stuck or want an opinion on something. As it is a place for current research rather than just-finished-research (aka the arXiv) or out-of-date-research (aka MathSciNet), then if I see something interesting, chances are that the person who wrote it is still working on it and interested in discussing it. And others know that what I write is what I'm currently thinking about so they're much more likely to say, "I see you're thinking about X, have you thought about how that links to Y?".