Can governements really stop Bitcoin ?
Every new technology , like the internet , can be used in a good way or in a bad way. On the internet there are scams , drugs , and many other illegal things. Does that mean we have to shut down the internet ? Of course Not.
In addition the real currency used by criminals is FIAT in cash (usd , euro , gbp ...) because it's not traceable. On the other hand , cryptocurrency transactions are made public on the blockchain.
Maybe some dictatorships will try to ban bitcoin although it's very hard to enforce because exchanges can just move to a place where it's legal , or be decentralized. But smart governements will just regulate it and embrace it.
most governments will regulate it but the problem is the details. what kind of regulation, what are the rules, what about the tax, etc.
those small details are the most important things.
It is unlikely that all countries will prohibit bitcoin, although some are already trying. I do not think it's possible to prohibit bitcoin everywhere.
In addition to the above comments:
Bitcoin and all public blockchain are using internet. If we talk about limiting the access, we should first observe which countries are already applying censorship on internet. It will give a good overview on the who and how.
basically China , islamic countries and some more