There is no assurance that Bitcoin will stay in the next 100 years. We never know what will happen in the future. There is a possibility that government will have a all through out battle against Bitcoin and ban it everywhere, or accept it as mode of payment or legal tender. We really never know what will happen in the future so whatever benefits we have today with Bitcoin, lets just enjoy it and hope it will last.
Good thing is no authority would be able to just seize Bitcoin itself since it is decentralized. The only worse possible thing that could potentially happen is get everyone behind the bars when others found out that they're holding Bitcoin or any forms of cryptocurrency.
Government alone would not be able to "Thanos Snap" Bitcoin. There would still be people out there that would be using VPN behind the scenes and also be able to trade locally. It's just not possible to clear out the swamp if it is everywhere anyway.
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This is true. I don't get it why people are so into legalizing stuff while knowing that regulation would come around after that legalization. I mean it's a double-edged sword, don't you think?