There is a lot of changes 15 to 20 years is very long time we don't know what will going to happen that time it is so hard to predict bitcoin may go up if it will continue rising based on thier past price rising from year 2009 till present, if it will continue it will reach more ATH in next 20 years from now but 1m$ is i think so high, no one knows about it.
$1 million is a pretty high price for anyone to hope for and it's certainly not likely to happen any time soon, as most people are expecting $80K to $100K in Bitcoin with a timeline until the end of next year. And this range is also the next ATH level which is more logical for everyone to expect if the level of demand and supply in the market can continue to increase this year for Bitcoin. Because I am also quite sure that price changes in Bitcoin will continue to occur significantly, although we also have to pay attention to corrections because that is also part of price changes in Bitcoin.