They'll probably want some kind of job to afford art supplies, but it's an option rather than a mandate.
This is oversimplified, of course, but it doesn't seem fundamentally impossible.
Nowadays with crowdfunding a writer could be paid by wannabe readers before the book is published, and only publish when he has obtained a FAIR compensation for his time working writing said book.
It seems like most are not using that model. Maybe it’s not lucrative enough; maybe they’re not aware of the possibility.
Kickstarters only work for known authors, so the newcomers would be excluded automatically from the beginning, but we consumers won't feel this for a few years.
Then it will stop being a novelty and hip thing to do (in about a week, given current attention economy), and the money streams will start to dry out, while the number of kickstarters will only increase while every existing author will switch to it.
Then Kickstarter itself and other portals will start promoting "better" authors, making it a sort of an unofficial ranked contest. Promoting will be based on different metrics, fairly as far as reviewers will think. Mostly it will be based on popularity and track record of previous products of those authors.
So the motivation to be seen on top (which equals - seen at all, due to the number or creators), will be releasing popular and catchy products, and as often as possible to generate a track record of good releases.
Over a few years this will shift people to create a common as possible popular and simple products, mandatory oriented on kids and ya because that's a gigantic market, so the lowest common denominator products will be the most successful and popular.
And so all kickstarter money, slowly drying out because more and more people will be tired of seeing this clown show and paying for inferior products, will be even further concentrated at the top kicktarting creators, while leaving "long tail" with zero money. Also audience will shift, while adults will stop participating in general, their kids will participate and will fund whatever is most flashy and predatory.
Thus this perpetual machine will go on in circles eventually producing only garbage.
We see a renewed interest of that with Patreon and other services.
(To simplify step 1, you could skip the thorny problem of defining who an "author" or an "artist" is by instituting a universal basic income.)
I thought we were talking about viable societies?
How can you expect any form of R&D investment if the investor can't expect to see an ROI? Sounds great if you want to stagnate but personally i dont.
If not, could you explain where you see a connection between copyright and R&D?
Almost all the money is skimmed by the huge range of industries that have arisen to capture the marginal proceeds created by copyright law.
Maybe you could argue that all artists are motivated by the folly of dreaming that they will be the next unicorn who actually gets rich, but I don't think most of them are that naïve. They find creating fulfilling. They would still do so with a UBI.