The best network, the best chain is nothing worth without people interacting with.

True.

And still there is something like a non-linear reward curve which is killing the growth of small, new users.

Not true.

Is the awesome tech just made to even better milk the system?

What are you implying here?

Does anybody has the whole picture in mind?

Yes.

If so, there should be a focus on user growth & retention!

Of course, I'm well aware of their importance!