I've seen and been with people with a master's degree that haven't gone to any Universities. They acquired a degree by submitting a papers correspondingly to their field of interest. How is this possible? Where is it possible to publish those papers? How can one publish those.
Perhaps you are thinking of a "PhD by publication", which is a different thing. See, for example, https://blogs.lse.ac.uk/impactofsocialsciences/2018/08/20/a-phd-by-publication-is-a-great-way-to-build-your-academic-profile-but-be-mindful-of-its-challenges/
I think that what you describe, especially acquiring a degree without university association, would be very rare, if it is even possible. Degrees are normally awarded by universities and there are usually many requirements. In particular here are normally attendance and course requirements, especially below the doctoral level.
If someone is in a degree program then a course might earn credit from on or more publications. There are also dissertations/theses that are primarily based on publications. But even those are normally done under direction of an advisor at a university.
I don't know the practices everywhere in the world, of course, but I would question whether the information you have is actually true. Is it possible someone has misled you?
I suppose it’s possible to physically not attend a university and still complete a degree, by correspondence, distance education or such similar means, or take courses for a graduate degree remotely and submit a thesis also remotely.
Either way, this is a distinction between being physically on site vs off-side, rather than just submitting a thesis without having been enrolled in a program. Most graduate programs have a coursework components, so if find it difficult to believe one can just submit a paper and get a degree (at least a reputable degree... whatever that means: I’m sure one can find corrupt institutions who will just sell you a degree with very minimal requirements.)