Is there any point in guaranteeing a job rather than just giving the person the money?

devil's advocate; doing a job takes time, whereas just getting paid does not. Making it harder to have an additional side-job. (it's a common belief that you need to be unemployed and looking for employment before getting a handout)

Also, whoever's "guaranteeing" those jobs can get work done, if you're into that sort of thing. e.g. digging/filling holes, or building roads to nowhere.

I agree. You can get full employment and a respectable standard of living floor through stuff like a negative income tax and universal health coverage. But making it illegal to work for what YOU consider a low wage and permitting labor cartels is counter productive.

When bargaining with a monopoly or oligopoly, don't unions just put workers on an even footing?

Market forces leave out every human factor. Unions add it back in.

Two wrongs don’t make a right. Let’s break up monopolies and encourage competition.

Is there an ETA for the break up? The trend is the other direction. We could always wait for the end of scarcity.

“Good laws can’t be passed, so we need bad laws (which we also can’t passed)”

Laws around unionization already exist.

Why are labor cartels bad but capital cartels fine?

Why must an employee bargain individually but a megacorp be allowed to bargain against them collectively?

Who here said any form of cartel is fine? If we need to regulate financial markets to prevent collusion, we should do that.

Why is a union collusive but a corporation and their HR department not collusive?

Calling unions "labor cartels" is cheap. You might just as well call democratic systems "law cartels" by that logic.