> Maybe I'm naive but I don't think there are a lot of "million dollar ideas" that are just being hoarded and all people have to do is share them

Often, the important things are the ones that we have already heard many times. ("Don't take drugs", for example.) Following these ideas consistently could already dramatically improve many people's lives.

Even if you learn something that most people don't know, such as software development, again there are relatively simple ideas, such as "write unit tests" or "prefer immutable values and functions without side effects". I am saying this as an example of an idea that may sound mysterious to someone outside the profession, but inside the profession it is just the boring advice that all of us have heard many times... but still many of us don't follow.

I imagine that there are things like this in other professions, too, and I would be happy to see their list. The important aspect is that those should be things that sound boring and obvious to people in that profession.

> This has nothing to do with intelligence and everything to do with negativity (and self-esteem, if someone is tearing others down to feel better about themselves).

Kinda yes, but negativity can become a cultural thing, if you see other people around you do that all the time.

Also, most people have a status instinct; it is too cheap to dismiss it as not having self-esteem. Probably the solution for them is to create a culture where being nice to others is the high-status thing, but that is easier said than done.