After that bitcoin will starting to lose btc price. But there are many altcoin has a potential to follow or overtake what bitcoin did. When there is leaving, there are always incoming and much better that the first came.
We can't say that right away, there's also chances that the value will rise if adoptions occurred,imagine if Bitcoin will be utilize and use in a daily transactions how big it can be in value, it's only 21M compared to the numbers of people and businesses around the world, there's also a high chance that Bitcoin will be mooning more.