People confuse academia with credentialism. Credentialism is a parasite that has long infested academia (ever since nobles wanted to send their children to study under the famous Greek philosophers) and now presents as its face. But academia existed long before Universities gave out credentials; in fact, long before Universities had undergraduate programs.

The Universities were, originally, just cloisters of academic scientists doing research (and sharing lab space), that you—as another academic scientist—would visit to exchange knowledge. And, guess what? Universities are still that. You don’t need to have a Ph.D (or the desire to gain one) to travel to any random University campus, walk into a research laboratory, and exchange knowledge with the people there. The core function of academia still goes on, though it is encircled by the parasite of credentialism. Or you can avoid Universities, and just work with academics directly through academic organizations, like one of the many Royal Societies in the Commonwealth, or through “industrial-academic partnership” organizations like the IETF.

Academia still exists even at the heart of purely-industrial think tanks, and government organizations, as long as they hire people with the enculturated mindset of academia. You think you can’t just walk into NASA, or Boston Dynamics, and ask their research scientists stuff? You can. Because they’re academic scientists, and so they will exchange knowledge with you (as another academic scientist) and consider it part of their vocation, whether it counts as paid job-hours or not.