These rich bitcoin holders are probably just holding their coins hoping to be richer in the future when the price increases. To say the truth 1 million of dollars is nothing nowadays to have a real rich life.
To live well they need to continue holding until bitcoin increases more its price and making investments meanwhile.
I agree with this sentiment. If you're 30 and hold a million right now, it just isn't enough to lead a real rich life. Once you factor inflation in the coming years, being able to live longer due to better medicine, you would need more like 5-10 million at least.