But they wont work for free if they are paper clip pushers or doing a dirty smelly job or being a maid or butler for someone else. Especialy the last example who the hell is going to do a job or servitude for fun?
There has to be some incentive somewhere.
Sure, there are crappy jobs that have to be done. A lot of them, though, are probably automated in the 24th century. Notice what Picard says: "The economics of the future are somewhat different."
and "The acquisition of wealth is no longer the driving force in our lives. ...We work to better ourselves ...and the rest of humanity."
They are not working to get rich; it's not necessary. That doesn't mean they're not receiving some kind of compensation for the jobs they do. Since only Earth is like this, non-Earth sponsored space travel and goods would need to be paid for. Vouchers or "credits" - as they called them in the Original Series - could be part of that. You want to live in a certain area? You like the mountains rather than the city? Well, as long as you work in your job, you get to keep that bigger property with the view. Everyone has a place to live, and you don't have to pay a mortgage, but if you want your dream home, you have to earn it. You have to contribute. Which leads us to --
"We work to better ourselves...and the rest of humanity."
That last part is key. This is why we're not a bunch of lazy fat-asses watching the game and eating replicated Pork Rinds because we don't have to work. They work because they are contributing to humanity as a whole. The implication is that by the 24th century this philosophy will be the human mindset, that we are no longer selfish schmucks.
Or maybe you get up out of bed and work in a less than exciting job because society requires that job to be filled. Sure, they're not earning money, but that doesn't mean people are not required to work. There would have to be a set of rules in place to ensure mankind doesn't pass out on the couch. Certain jobs have to be done and while everyone would have a choice, there would always be people who "don't know what they want to do when they grow up." You can't think of something to contribute? Then you have to pick a trade from a list of jobs. If you wind up really hating it, you can apply for another job, but you have to do something
. You could work for rights, privileges or even levels of citizenship. Want to run for public office? No campaign money needed. Instead you work for points. What have you contributed to society? The more service you do, the more points you earn, allowing you to run for a higher position. Lots of other things besides money can be used to motivate people.
Window washing? Probably obsolete. Many cleaning services and stuff? Automated or maybe androids take care of it. Not every "picking up shit" job has to be done by leaving, breathing humans. Also consider that not everyone working today does "unpleasant" jobs because they "have" to. Many people choose that trade. Even if you can't imagine doing it yourself doesn't mean everyone feels that way. I couldn't possibly imagine crawling through filthy air ducts, breathing insulation and dust to repair industrial a/c units. However, my son does. He chose that trade and enjoys it. So maybe someone picked butler or maid because it was something on the list they felt they could do well. How many maids did we see in TNG? The one in the final episode? She served Data tea, but we don't know what else she did. Nobody said she cleaned toilets or dumped the litter box. For all we know she watched the place and kept the robot staff programmed. Or maybe her family lived in that house as caretakers for centuries. Tradition could play a big part in careers.
So, yeah, society without money and leaving it at that makes no sense. But it was always vague enough to allow the idea that something replaced currency.