Status, enjoying the job, altruism.
The odd thing is in capitalist societies we reward the jobs that give the above with good pay.
We rely on coercion,...
That's not the same as being threatened to be thrown into the gulags just because you refuse to work in the coal mines. I wasn't coerced into becoming a machinist, I was
incentivized into perusing that path because it payed far much more than being a retail associate for the rest of my life. I had to evolve, pick myself with my own bootstraps. I was not forced at gunpoint to work in the coal mines by a commissar.
I don't evny the doctor who gets paid more than I do since he has gone through the task of going through additional education and residency for his/her efforts to become a doctor (Doesn't matter if it's a general practitioner or a specialist like a cardiologist). Teachers are a mixed bag, at least here in the US, since it's dependent on the school district, what level of education is being taught (elementary teacher vs. college lecturer), public v. private school teacher, and what contract the teacher's union have negotiated into and that's a whole mess that involves the superintendent, the K-12 school board, and the city/town mayor and/or council (This is more seen with public schools in the US).
...specifically having enough to eat, somewhere to live etc,...
Those aren't coercions.
...to get people to do the jobs that don't provide status, aren't enjoyable, don't leave you feeling good about yourself.
And
how are you going to incentivize the people in this communist utopia to work the dirty jobs that are essential to running a city, a civilization. Without resulting in authoritarianism? You're
still going to need manual skilled labor jobs to maintain the necessary infrastructure for a modern society. Not everything can be replaced with robots and AI, there's still a task that needs the human finesse and judgement that a machine does not posses. Even when working on a CNC machine, I
still have to take measurements with calipers and micrometers to ensure the cut is to tolerance and make any adjustments necessary.
As Perfection brought up, "Everybody wants a clean toilet nobody wants to clean the toilet".
Even if you go completely communist, you're not getting rid of any system of monetary exchange as the system would evolve into a black market where capitalism exist out of the prying eyes of the communist authorities who would crack down on the system, harshly, if they discover it. Hence communism devolves into authoritarianism since you
need a crackdown on a shadow economy that undermines the communist system and forcing people to work, under the threat of punishment, jobs that you'd describe as "don't provide status, aren't enjoyable, and don't leave you feeling good about yourself". Even under communism, you still need workers to mine the coal for the people's coal power plant or materials (coke) for the people's steel mill.