Why do we keep electing politicians who don't represent us

I have yet to see a politician that isn't a lying, selfish, fraudulent, criminal, corrupt, problematic pasted, greedy, power-hungry, dubious self-serving bag of rotten egg crap. Decent people with morals and values don't want to be politicians and represent their peers, because they know the kind of idiots they'll be forced to deal with on a daily basis

I have come across plenty.
My current MP is one of them. He is a decent, hard working man doing his best to support his constituents, and to fulfill his role as an MP. He isn't the only one by a long way.
One issue is, we tend to only hear about those in the spotlight, not the other 600 or so, many of whom do a great job. The press aren't interested in a headline saying "MP hold constituency meeting in drafty Church hall on a Saturday morning, then follows up the information (s)he has been given and works hard to support the people in that situation".

But surely that is the point ?
People don't want to die before they are ready to.
People who choose to go to Dignitas (and can afford it) have to be well enough to travel. So some make the decision to do so as it is the only way they have any control, rather than having an extra 6 months or year, living with their loved ones, still knowing that when the time feels right for them, they could choose for their life to end.

Please can you explain to me what you mean ?

I support Dying with Dignity, and a person's right to choose when they die (with various safeguarding checks in place). My friend disagrees with it. My MP can't "represent" both of us, as we have opposing viewpoints.

Or are you saying each MP needs to set up some sort of referendum before they vote on an issue in Parliament ?

It’s one thing to feel you can’t support the Assisted Dying Bill, but another thing entirely to wish someone would suffer the consequences of not supporting it in ’exquisite detail’.

Because people have different views on who we think represents our preferences best. 🤷‍♀️

You misunderstand representative democracy.

It is not meant to be directly representative of each individual, how could it be?

The point is each constituency sends a representative to make a judgement call on the issue in front of them.

Why do people vote for the politicians they vote for?
We all have at least three issues which we feel strongly about, probably more.
Do you vote for the candidate who meets all or most of them?
But what if the party that they represent has views on other less important issues which you strongly disagree?
You may feel "I'd never vote for X party ... but I agree with them on d, e and f". You may vote for Jo Bloggs who got you something you brought to them.
Some issues are amorphous. Independence, Brexit - your opinion of the issue and desired outcome may be diagonally different to what emerged/emerged.