I think the worst enemy is the bankers, crypto will be the end of banking, as there will be no need for them, thank God for that, The bankers are the biggest criminals in the world.
Maybe some banks that support bitcoin will someday sell their bitcoin in bulk, I'm sure one day the bitcoin price will run out
If that future is truth in someday, I do not think Bitcoin can keep function decentralization of it. You also know decentralization is one of interesting point of Bitcoin and cryptocurrency. If in someday, this function disappear, I believe number of Bitcoin users will decrease many much.