Governments ultimately draw their authority from their ability to keep their citizens from overthrowing them... China is doing a good enough job right now, even if you don't think so, and even if there are some bad things happening there. But the reality is that even if they were to submit to internationally audited and monitored elections overnight, it'd still be subject to the flaws of a democractic system (private interest group, big money influence, etc) that would taint the ideal of a fair election. A democractic election is ultimately still a proxy of power distribution. You'll end up with more of the same most likely, but with less excuses to point fingures at when they commit unpopular acts (for example they may still imprison Uighurs, expand in the Indian ocean, and threaten Taiwan).
Rather than making such strong remarks telling Chinese people what they are, you can just go there and ask them yourself instead of armchair posturing.
China is a slave country controlled by dictators against the will of the people, not just "a different culture".