However, Bitcoin is still accessible to everyone, and anyone can accumulate it.
Bitcoin always been accessible since the first time release. 
If you divide 21 million bitcoin by 8 billion people, there's enough bitcoin for each person to have 262500 satoshi'.
But millioner/ billioner are accounlate 30% of total btc amount so what happen the price if whole of the world aware about btc?
Where's the proof if the millionaires and billionaires hold 30% of total Bitcoin? sum of all ETFs, countries, companies and DEFI is only 12% of total Bitcoin.But millioner/ billioner are accounlate 30% of total btc amount so what happen the price if whole of the world aware about btc?
If you talk about Richest Bitcoin address, most of them owned by centralized exchanges or entity, technically it's not their money because they only hold other people coins.