I'm sorry but those predictions are based on nothing. There are 21,000,000 bitcoins. With those predicitions the total bitcoin value in 2035 will be $ 21,000,000,000,000,000. I hope you understand how ridiculous that sounds......
Preserving your statement for history. Saying the dollar won't be worthless in 20 years is the same broken paradigm logic of every Fiat holder EVER.