That might have been more accurately stated as:

"Want to hire people to cure polio, go to Mars, put LED lighting in every home in Africa, fund research into fusion reactors, build flying cars, or push VR into the mainstream? You'd better have some cash."

It's rarely the people with the big money that are doing these things, they're just hiring people and having influence on direction. Sure, they might get credit for being a "visionary" or "innovator", but the people doing the real work rarely make the big bucks (or get much credit, unless they're very lucky).

But, in fact, the very people with lots of money who are influencing these developments are themselves influenced: often by people with not nearly as much money -- such as relatively poor authors, or other "real" visionaries.

So you could also say something like: "Want to have some really significant influence on the world? Write a book." It doesn't take a lot of money, and it's not certain that you will be influential, but if you have some really great ideas you might stand more of a chance of changing the world by writing than by trying to compete with the likes of Gates or Musk for the really big bucks.

Of course, lots of other cultural artifacts have also been hugely influential. How much of our modern world has been influenced by Star Wars or Star Trek, or by mathematics -- which really makes all those Mars journeys possible in the first place. How many people have been influenced and inspired by music? All of the arts really feed in to and greatly influence each other.

So there are plenty of ways to influence and change the world apart from being rich -- and many of them are even more effective, as these other means could influence many generations of people -- poor, rich, and otherwise.