UBI is meaning enough
At some point, we are going to need a universal basic income (UBI). Human biology moves slower than silicon tinkering, so it's only a matter of time until we fall behind—machines will outperform us on every front not just physically but socially, intellectually, creatively.
When that day comes, the choice is between a hyperinequalistan whose small class of uberweathy grows ever richer off the dividends of ancestral wealth (while the bulk of the population starves on the offal), and a UBItopia that offers everyone a minimum of decency.1 2
Because there are no real alternatives in a world of human redundancy and because the first option seems so bleak, many of the technocrats I follow take a future UBI for granted. Only psychopaths and Ben Shapiroically pure conservative idealogues can reject the UBI outright.
Thus, much of the discussion around UBIs begins with the premise that it has already been adopted. Technologists prefer to deal with questions like: What effect would a UBI have on human creativity and artistry? What will society look like with most of the population unemployed? And perhaps the favorite: how will people find meaning post-work?
Here's how Elon Musk puts it:
[The] much harder challenge is: How will people then have meaning? A lot of people derive meaning from their employment. If you’re not needed, what is the meaning? Do you feel useless? That is a much harder problem to deal with. How do we ensure the future is a future that we want, that we still like? 
What Musk and other technologists forget is that most people derive meaning from their relationships, not their employment. The majority of people are—to put it mildly—ambivalent about their jobs. They would be perfectly happy to stop working and never look back. For this population, jobs are a source of meaning in so far as they are a place to develop relationships with others, and most jobs aren't particularly well-suited to doing even this.
Work that is deeply fulfilling and intrinsically meaningful is the exception; it is a privilege and luxury reserved to a tiny fraction of the population (usually already wealthy technocrats and creatives). What Musk was really asking is: "How will I have meaning? I derive a lot of meaning from being the spaceships-EVs-solar-panels-and-tunnel-boring-machines dude. If I'm not needed, what is my purpose?" And that might be a hard problem for you, Elon, but it's not the main concern for the rest of us.
Fortunately, we already have a time-tested solution for creating meaningful relationships—it's called community. And you build one through shared events like sports, barbecues, volunteering, schools, the occasional acid trip, etc. It really doesn't take much imagination: go share a cup of tea with your neighbor and stroll around the block.
It's not a coincidence that the happiest countries are those that work the least (think of Southern & Northwestern Europe) . That the Netherlands with the highest part-time female workforce participation in Europe  also happens to have the happiest kids in the world . That the world's monied classes have historically prided themselves on not working (our own culture's cult of work is an abberation).
When we talk about creating meaning after employment we're distracting ourselves at best and fostering complacency at worst. Meaning after employment isn't the problem. Meaning right now is the problem. The real "harder challenge" is to strengthen local communities and institutions long before the last humans become redundant.
This is not just a hard but urgent problem when our communities are falling apart from suicide, addiction, overdose, and chronic disease . But it doesn't have to be a particulary difficult problem to solve when the most effective solution has already been identified: the UBI.
Economic security is the primary precondition to creating any kind of meaning anywhere. That's because, as Orwell puts it, poverty "annihilates the future." You can't even begin to create meaning and deep relationships when your mind is flooded with the worries of paying bills, getting enough to eat, finding your next fix, etc. As he puts it yet more poignantly: "Poverty is spiritual halitosis." Solve the underlying economic uncertainty first, and much of the spiritual growth will follow by itself.3
Let's get back to the challenge of implementing a UBI and fostering meaning right now. That's hard enough as is.
Counterarguments to a UBI that invoke the slippery slope ("Who defines what is minimum? The UBI will have to grow larger and larger to satisfy us.") totally miss the point. What other purpose could we have as society besides making the general population steadily more prosperous? ↩
Persistent exponential growth (as in economics) tends to collapse highly complex multi-dimensional problems onto single axes. This is why gases of billions of particles are characterized wholly by three variables: pressure, volume, and temperature. And this is why on a centuries-long timescale the societal choice simplifies to a choice between unbounded inequality and redistribution. ↩
The conservative talking point of government handouts fostering complacency and spiritual degradation is completely backwards. These pundits need to read more Orwell. ↩