US national level politics has been stuck in neutral for a while. But local and state level governments have been often doing pretty well. So although it's not visible on the surface, I think US democracy is doing "good enough". I think a key here is that one person / governing body really doesn't have all the power here.
Fox News is populist media; populist media is a "feature" in practically every country. On the other hand, populist media on the "other side" exists without too much conflict here so far. There's also more sober sources of information too, for those that feel that both are pretty junky. Honestly, the fact that polar opposite populist mouthpieces can both exist is probably a better indicator of democracy than the fact that a single populist media outlet exists. If one had to ding our democracy at the moment, it's that high level government officials in the US are trying to discredit media sources more than in previous times. It's not censorship by any means yet, but it is something to watch (and, if one was a US citizen, seriously push back on).
China will be interesting to watch too. Although they've come a long way, they are still a middle income country by PPP. I can't think of any high income country of late (other than petro-dictatorships) that hasn't embraced some form of more democratic, more open model. Xi Jinping is going in the opposite direction.
The interesting question is whether his current concentration of power will satisfy, and truly keep the stability they seek, of all of the 1.4 billion people in China... especially at a time when China's middle class is rising. I also wonder whether the current control tightening of information, and a reluctance (so far) to ease off the heavy handiness of government involvement in business, will harm innovation in China in the long run. We'll see -- not being Chinese, I obviously don't know enough to wonder anything other than some vague "armchair thoughts".