Although regulations may reduce our anonymity or lessen privacy in transactions, as long as the system remains intact and functions the way it’s designed to, Bitcoin will remain unstoppable.
Nobody can do that at protocol level (lessen our anonymity or privacy in transactions). All they can do is to regulate
centralized services like exchanges. Bitcoin is like cash. When you go to a super market and buy something and pay in cash, the owner doesn't ask you for your identity to make the payment but when you use a centralized service like banks (eg. debit/credit card) you have already revealed your identity.
It's the same with Bitcoin. People don't want their privacy be invaded, then they shouldn't use centralized services with their decentralized money called bitcoin.
Well, it's very possible that when you purchase at a grocery store, you just pay with Bitcoin and they'll never know who you are. But what about the point where you purchase that Bitcoin? Sure, most of us use our bank to purchase Bitcoin on an exchange, so at that point, we've already revealed our identity to the exchange. Since the government regulates exchanges and banks, they could obtain that information.