Bitcoin is actually applicable to anyone. Provided each and everyone has access and the means
to acquire them. Connectivity is essentially a major requirement and knowledge of the way
cryptocurrency functions and it's applications around. But it seems not everybody is drawn to
the idea, since a lot are not really that familiar with bitcoins influence and significance today.
Rich and wealthy people do have more advantage over others, they are very well funded and
are capable of investing in large amounts, hence have bigger pay outs. The decentralized part
of bitcoin rest assures the high possibility that anyone at anytime and anywhere in the world,
bitcoin is available and ready.
Surely rich people will have the advantage they can adquire more coins than the rest of people, but I think the main point here is the accessibility. Anyone can have access to Bitcoin, it's equal for everyone, as it's decentralized.
There are traditional investments in fiat that have as one of the requirements a minimum amount of money to invest, that is usually high, not being accessible for poor and average people in general. Also, profitability in BTC is higher, so poor people can finally invest their money and make it grow.
The difference in terms of investment size will surely exist, but in terms of accessibility won't.