> Unfortunately, also in academia you cannot just do what interests you, unless you got unlimited funding somehow.

Okay, but you cannot be both in academia and accepting someone else's funding to work on their problems at the same time. Once you accept the latter, you've moved into industry.

That's not to say academia becomes off-limits. You can also spend time out of your day working on your own pursuits — you get 24 hours to divide as you please. But when your time is focused on someone else's interests, you are not in academia. You are in industry.

Huh?

There is sometimes external funding from industry towards academia with a concrete research and there is internal (taxpayer/internal money) funding in academia. Both are not handed out freely.

There is basic research, not tied to any concrete practical problem, but there never is random research. Professors have some freedom, but have to answer. The type of academia you describe only exists as a wanted Utopia, not as reality.