I’m having trouble finding v-dems actual arguments about this
Not sure what you mean by that. You can select any single value you want, select the country, and then see the scores over time. Or see the by-country scores with different sections broken out here.
I again have to ask how you think elections in china work, do you deny the existence of their elections?
I certainly deny they have free and fair elections, yes. There's only one party on the ballot - that's a hell of a lot more than a "preference". Elections in the People's Republic of China occur under a one-party authoritarian political system controlled by the Chinese Communist Party (CCP).[1][2] By law, all elections at all levels must adhere to the leadership of the CCP
"The majority getting what they want" is way too vague of a statement to quantify, but generally speaking I would agree that people in America and most of the Western world are dissatisfied with their governments. That doesn't make them undemocratic. I get your argument - you're saying that if people aren't happy with the decisions their government is making, is their government really representing them at all, and therefore democratic? But politicians making unpopular decisions has always and will always be a thing, and to a certain extent it's necessary - it doesn't even mean the politicians are corrupt for doing so. With that said, overall, I'd say that most major government policies are politically popular.