States holding such a big amount could interfere too much into Bitcoin's power equilibrium.
Starting from mining which runs on a 51% rule to fees which is dependent on average transaction fees in that block to even then whole bitcoin price which depends on selling and buying rates that in turn is dependent on major holders and whales.
The fact is what really can anyone do???
The only thing is bitcioners can try to hold as much as they can hopefully the government doesn't get hold of enough coins to violently shake the market.
Bitcoin's maximum supply = 21 million BTC
So 51% of it is 21,000,000 × 0.51 = 10,710,000 BTC
51% of Bitcoin = 10.71 million BTC. If only 10.71 million Bitcoins are in the hands of any individual or group, they may be able to interfere with the entire network in a dangerous way. This is actually the point of the existence of decentralized Bitcoin. So can a country's government or a large group destroy any established technology (Bitcoin) if they want ? Ordinary users like us this is why keeping Bitcoin decentralized is so important.