You still have a chance to be a millionaire through Bitcoin... If you have the guts to invest a big amount of money in cryptocurrency however even if you invest a big amount of money you can't still be a millionaire if you don't have enough or proper knowledge about the market or trading.
You can gain profit from the volatile market take the guts on buying on the bearish market and earn a lot in bullish market however the risk of investing to a volatile industry is high so you should know the considerations you might get in investing to cryptocurrency industry.
Well you will also have chance even if you have invested a small amount of money but it will surely requires you a lots of effort to achieve it but whether small or big everything will depends on you, on you skills and knowledge, on how you analyze the market, the charts, that will dictate whether you will earn or not in bitcoin. After you have exert lots of efforts and money on bitcoin i think you can achieve what you want to achieve to call yourself a wealthy man.
In my opinion, the only thing that is required to get benefit from bitcoin is taking the decision to invest in it. The early investors never imagined bitcoin to touch high marks of 20k dollars but this happened. They took the chance when no one was even willing to pay bit of attention to bitcoin and then, they just hold it out of trust. Invest some money in bitcoin, trade in it or hold but never sell it out of fear.