PoW don't need to be replicated. Banks/govs can create a PoS system with several central forging servers. This is just an example and there are more solutions.
PoS , especially PoS controlled by corrupt parties who knowingly break the law, repeatedly, isn't secure . Additionally, you fail to address my other points. It isn't just speculation as well -
But all these things won't make price go up. Basically, I want to say that dreams about $1-3-5k and so on per coin are sick.
Actually , you haven't done the math. Lets assume a fantastic premise to bolster your flimsy argument. In the extremely unlikely event that bitcoin becomes illegal in every country thus eliminating the whitemarket, heavily criminalized with severe penalties thus eliminating the grey market, it will be used just on the blackmarket.... and if it grows to only encompassing a very conservative 5% of the blackmarket you are talking about 100k dollar coins eventually.
Bitcoin has already reach critical mass and will continue to grow.