Why isn't a postdoc a real job? A postdoc is a professional position in a research institute working as part of a team under a more senior researcher. They're normal full-time salaried positions with career paths everywhere that I've seen them.
Depending on location, there may be mechanisms to preferentially hire a postdoc on as non-tenured faculty. It became more common in biomedical sciences after the recession when grad students stayed on for "postdocs" with their advisors when they couldn't find a job, and were then aged out of the postdoc.