Now, I do think you're just trolling OP.
You have basically just asked mumsnet to explain the meaning of life. Lols.
Why don't we all top ourselves is just a variation of the same question, the same one that every philosopher has grappled with since the dawn of time. You haven't just emerged from a chrysalis and suddenly discovered a secret truth.
Everyone, at some stage, grapples with this question.
The answer is, we don't know. We don't know why we have developed a survival instinct that stops us from topping ourselves once we realise that we are completely insignificant. We don't know why all species, from an amoeba to a human, has developed the same instinct.
So, unless something has gone very wrong chemically in the brain, you are unlikely to ever be able to override that survival instinct, no matter how much of a drudge life becomes.
With that in mind, you have to choose to make the best of it. Objectively, not everyone is a wanker. If you are are attracting non-stop wankers in your day, you have to ask yourself why that is happening.
It is possible to enjoy life most of the time, even with non stop chores, if you accept you're going to be here anyway. I like the phrase "if you're not changing it, you're choosing it".