I know how I would set things up. But in the vast majority of cases there are objectively good and bad policies and the fact that people voted doesn't change whether something is a good idea or not. Nobody's voting in China as far as I know and they've seeing unbelievable rates of improvement in their living standards for the last few decades, it isn't that hard.
The issue is that the political class (really any group of people) is inevitably stuffed with corrupt sociopaths, tends towards groupthink, is easily dissociated from reality and insists on using social proof rather than a scientific approach. The system as it stands is just a big complicated stick to wallop them with a Trump every so often if they really muck things up to the point where their incompetence triggers too many problems for enough people. The exact trigger % of people needed to engage the stick should be set sensibly but in practice the US is making do with around 20% of the population according to Wikipedia [0].
I believe it would be straightforward to determine policy if we had an oracle with perfect knowledge that operated under a so-called veil of ignorance [0]. Getting good outcomes with a fair & reasonable minimum standard of lifestyle for the people who are the worst off isn't particularly hard. The problem with implementing that system is the lack of oracles and deficits of intellectual honesty.
The key point is we don't need to vote to determine what works well. Whether a policy gets good results is just a fact regardless of whether or not people vote for it. And there are a large number of policies that were terrible the last time people tried them and will continue to be terrible even if the voting public decides to try them again.
They vote from an approved list of candidates, but the following makes it sound as if, in principle anyway, there ought to be enough voting to keep the better apparatchiks and bounce the worse ones:
("The People's Daily* says the grass-roots general elections in mainland China are the largest [900 million voters] grass-roots democratic elections in the world.")
