The difference is that the purpose of government in China is to govern effectively. They dedicate resources to producing leaders who have proven they can govern at lower levels to some degree (you always find that the corruption in China comes from leaders who came up through SOEs or similar). In terms of civil service and province-level leadership, it is just incredibly effective.

In the UK, you have leaders who are incredibly unpopular, they have no real skills, and they spend most of their time pandering to very small groups of people for various reasons. There is no real incentive to do anything relevant to voters, in fact you have seen over the last five years that political engagement has dropped significantly in a way that has generally benefitted incumbents.

To say this another way: the point of the UK system is so that people who are manifestly unfit to govern end up governing, and a small rotating group of special interests are continually pandered to (there is complete blindness to this in the UK, people often assume this is wealthy people when wealthy people are largely ignored...a politics grad working in research for a think tank will have more power in actual government than someone who gives £10m to the governing party).