@The_Compassionate_Heretic initially of course man power would need to be invested to build said machines, but as far as needed people to maintain this devices, you wouldn’t necessarily need manpower to maintain and repair them. you could do this by a couple different ways.
you could build them in a circular manner, meaning machine A has two jobs, one’s to build cars, the other is to fix machine B, while machine B processes food, it also has the capability to fix machine C etc etc etc.
the other, more realistic option. Is to build a vast surplus of designated repair machines, these machines not only are suited to fix other machines of various tasks, but are also able to fix other repair bots.
And I was just saying that if money didn’t exist, people wouldn’t have to work in order to make a living, so in most cases, people wouldn’t work. So you’d need robotics to take their place. And you’re right, currently Robotic tech isn’t able to handle something like this, I just assumed you meant in a futuristic setting.
Obviously if you just rid the world of all monetary value today it would completely collapse.