With bitcoin as well other cryptocurrencies there is nothing assured, it's all about speculation. Market scenario change with time, also the market adoption is much needed for a large scale growth. Till last year users didn't had big expectation on the peak growth, but after it reached above $20000 the expectation has grown high. We users can just hope for the best to happen.
What are the pessimistic/Sane/optimistic and wildly optimistic predictions for the 2021 price of BTC in your opinion?
I'd say the BTC will hit the $10000 before the end of 2020.
Plus predictions are just you know "predictions" we can never know whats going on / what will happen in the crypto market.