Bitcoin is for everyone, it's the most decentralized currency to ever exist. These big companies and rich people you see buying Bitcoin now weren't early to Bitcoin, they just started buying Bitcoin once it went mainstream. In the early days Bitcoin had a much more cryptopunk feel so hopefully we can recapture that feeling. I feel like these huge companies buying up large swaths of Bitcoin don't have the best intentions, they want to take it from a decentralized miracle to a centralized abomination. We should all work to keep bitcoin decentralized.
They can't do anything to the decentralized nature of Bitcoin by buying and owning a large percentage of its circulation. All they can do with that is manipulate the price if they want to by creating walls of sell or buy orders and forcing retail traders to either sell low or buy higher so that they can fill their bags with more cheap coins or sell their assets at a higher price with that manipulation. Their buying bitcoin in large numbers is only a positive thing for the market as a whole because the more they buy, the less there will be in the markets, and if demand increases, its value will increase too.
Coming back to the topic, of course, Bitcoin isn't only for the rich, because someone with even $10 can start buying Bitcoin, the only thing is that you won't be able to make much profit with a low investment, so one could say that the larger your investment is, the more you are going to benefit from Bitcoin, or other cryptocurrecies, but other than that, if we talk about its use cases, then it's obviously for everyone.