The point isn't that it wasn't hard work to grow from $250,000 to billions. The point is that there's a big difference between saying "anyone who works hard can build a company like Amazon" and "anyone who works hard and got $250,000 from their parents can build a company like Amazon."
Anyone who says that (anyone who works had can build a company like Amazon) is a fool. Most likely suffering from survivorship bias.
You cannot. But Bezos did not inherit billions and living on them. He is self made, maybe he did not start at zero, but he did 1000x or 10000x (or even more) what he received. If someone had received a loan of 1000 dollars, I doubt anyone would say he isn't self made when he reached a million.