There is multidimensionality on PhysicsSE insofar as one can look up what types of questions a person has answered. One can look at the tags section of the user page, click on a tag that is relevant to you (for a particular question, perhaps), and look, for example, at both the first page and last page of the answer list associated with that tag. If today you look at my page, you'll find that I've answered lots of questions on QM, with 15, 10, 7 upvotes at the head of the list, and with three -1's. In other words, I can sometimes be unconventional, but on elementary questions about technical matters I can usually answer a question on QM well enough. For someone else for a specific tag, you may find that their answers never have an aggregate number of downvotes.
If someone is a newbie, there's nothing for it but to assess their answer for yourself and/or wait to see whether they get up-votes or down-votes and/or comments from other people.
The tooltips on the tags page for a user gives numbers of questions and answers and the total reputation gathered, which gives faster but slightly less detailed clues.
This may not be a social network site, but one certainly gets to know and respect the strengths and weaknesses and views of some of the main questioners/answerers after a while, although user pages may be more or less completed. I think of this as a social endeavor site.