Actually, I am in agreement with you. That's why the term "Sitting" government is important. Bear in mind that in British or Commonwealth general election, you are electing a candidate to the role of MP (Member of the Parliament) which then is the sitting party who assigned which role you will serve under the ministry, as that, a role of Prime Minister or say Minister of Trade would have carry the same weight. And that had been the way since the issue of Westminster System back in 1850s (or something like that)
First of all, vote or democratic electoral system is not to vote "The Most Qualified" representative to run a county, simply because of its "multi-Party" system. I mean while a conversative saw a candidate as most "Qualified" I am pretty sure the people who voted for Labour would not see it that way. That's the beauty of democracy election process, you get your say, and you get your choice, this has nothing to do with who is more capable of the job. This is about party and what kind of policy you want to enact in your country, that's why you VOTE for your party candidate.
Secondly, you may think Brexit is a bad idea (Or Boris, or Truss or Sunak), but coincidently majority of British does not seems to think so, that's why they voted out, and unless you are British, your opinion does not really count here.
And finally, I would not say this is a joke, maybe for you Chinese, but then you weren't actually "Chinese" chinese aren't you? So as
@epebble said, I don't know what is so funny on it. As a person who hold a British Passport, I see this as democracy at work, so I don't know what a Malaysian think about what Chinese think about something. Now, that's a joke.