Bitcoin is not the only project using POW so far, but the only thing the government is targeting is bitcoin, it shows that they know they can't control it, and they don't want to see it grow to threaten their power, not because POW is a waste of energy and a major cause of global warming.
Indeed, we cannot know the future of bitcoin if the government really wants to get rid of POW completely to secure their power, but let's hope it can last and will not be changed.
I still can't understand how they say that Bitcoin with its POW causes global warming because the device for mining it uses fossil energy to run, even though bitcoin mining only impacts 0.1% of world pollution and air pollution caused by coal-fired electricity generation is much bigger compared to Bitcoins. It seems they turned a blind eye to the facts before their eyes and let it go. They're just afraid that the adoption of Bitcoin is getting massive and they can't control it any further, so they raise issues like this and make a lot of people think that Bitcoin, which is one of the main culprits of air pollution, actually isn't.