Why are we mixing possibilities with prediction? I would suggest you to check it again as it's not a prediction but rather possibility as we are already aware that anything is possible in crypto it may either cross $100000 or even drop down to $100. I personally think figure $100000 is bit overhyped and might not be an easy feat to achieve by 2021.
Maybe this is the part of the hype over the past weeks to boost the price of Bitcoin but it wont happen easily even if we want it this is also an overhyped prediction. Bitcoin is the best coin but we have to see the real situation of the market and don’t just believe on any prediction, 2021 might be a good year but no one can assure that.