The government have tried alot of times, but they can't kill it, how can they kill something they have no control over, bitcoin is a decentralized digital currency that doesn't depend on any government to continue working, so the government can't kill it, they can only prohibit the use of bitcoin as many countries have been doing over the years, but there's no way the government kill bitcoin totally, it's just  like the dark web, the government can't shut it down up till today.