Millions of companies and indie developers have a platform to make money. This never existed before.
Amazon, Google and Apple also employ thousands of SWEs that make a good living building these services for customers.
Bezos doesn't "make all the money".
Not only that, but the rich tend to be the early adopters of these very innovations - that is, capitalism begot these innovations specifically to cater to those able to afford them, and only later (after the requisite infrastructure and economies of scale took hold) did they serve as any sort of boon to the common man. Electric lighting and automobiles are two particularly-egregious examples, and they continue to be examples to this day; it ain't the rich who are still reliant on candlelight and animals pulling wagons, after all, but rather the poorest of the poor.
The economy is NOT 0 sum. Inequality in itself doesn't doesn't do anything bad. Billionaires existing can be true while poverty shrinks.
IMO it is a low value argument to state that we could fix world problems by removing "inequality". I'm happy to be proven otherwise.
BUT we need to somehow poke holes in the billionaire that don't both totally drain them or leave them unharmed. The holes need to be large enough that they can help the government support the people.
Problem we have is that the billionaires bought all the hole punchers and aren't letting the gov use them like they used to.