10 Million dollars for the bitcoin is very realistic because the highest possible price of bitcoin is only 100k dollars and even that is very low chance to happen only because bitcoin now is very low price and we don't know until when is this.
Am I misunderstanding your statement? 10M dollars is very realistic but you said that the highest possible price is 100k dollars only? Or did you mean to say "unrealistic"?
For me it is even hard to reach its last year highest price again in the next 10 years, of course hard does not mean impossible. Chance is always exist but I do not know what will make its price raising again. As a trader, I will just follow the price movement and take all possible chance to make profit. I wont hope too much..
although all things can happen but to achieve such a high price is very difficult to achieve, what is the reason so that prices can reach $10 million per btc? even the gold used by everyone in the world does not reach that high price? Will the price of bitcoin be that high if it is used by everyone? I dont think so