I think that Bitcoin will never go up in value to one million dollars. The states will not allow this in any case. It is no coincidence that the issue of cryptocurrency was already discussed at the G20 summit, but so far it has been decided that cryptocurrency does not pose a threat to global financial stability. If the decision is different, then the reaction of states will be different. No one will allow large uncontrolled capital flows on the territory of the state. Therefore, certain response measures will be taken to prevent this from happening.
What does the state have to do with it when bitcoin is decentralized. Countries can impose a tax on the use of cryptocurrency, which has already been done. An excellent article, written in 2019, the time is slowly approaching, thereby giving a sign of the rise in the bitcoin rate.
If a cryptocurrency intends to circulate on the territory of a state, then this state will definitely determine the conditions for its circulation. At the same time, it does not matter at all whether it is decentralized or not. I think it's not a secret that money greatly influences both the policy of the state and its economy. Therefore, the state cannot stand aside from this process.
The state, by its regulatory measures, is able to influence any processes within this state. Therefore, if states want to prevent bitcoin from reaching the price of one million dollars, they are quite capable of doing so.