The vast majority of professors, I'd say, are like that.

In startups, it seems that a strong ego is an advantage - if not a necessity (see: Elon Musk, Adam Neumann, Steve Jobs). There's an attitude (usually explicit, but sometimes implicit) of "we're disrupting the _____ industry and changing the world!".

Overall, I think you can find strong egos in any industry or job. However, my guess is that if you (somehow) ranked researchers and founders by ego, you'd find that the distributions were quite different. My guess is that the majority of founders have strong egos, with a long tail of those less ego-centric and that researchers would be quite the opposite - generally less ego-centric, with a long tail of strong-ego individuals.

Regardless, I'd say the definition of a "successful researcher" is usually someone who has become a professor.

Whilst there are many great postdocs, very few (any?) of the good ones become professors.

This could be interpreted favorably toward unsolved problems, which some of us still have thousands of, most of which will remain unaddressed forever.

Any solution requiring significant (or especially massive) effort can most confidently be undertaken the more obvious it is.

To some extent might as well pick an obvious one to invest major effort, where even sporadic progress will at least all be in the correct direction.

It could be good to put a lot of that under your belt to help better approach the less obvious problems, even if there is already an unfair advantage about things which are not so directly visualizable.

There could be unique outcome among your obvious problems if you choose one where others do not see any visible solution at all.

And you can become more ready for things put in front of you.

As a trained mathematician it certainly mirrors my experience. Banging away at a narrow problem typically either results in a) no solution or b) enough bullshit to convince everyone that you know what you are doing. The latter is sufficient to carry a career in many branches of pure mathematics.

What usually works better is understanding the holistic environment around the problem, which is not always obvious at the outset, and then the "problem" becomes this little hole in a fabric of understanding and we go "duh" and solve it.