Humans aren't like that. They don't deprive themselves of activity like a bored dog unless you (who?) give them a job. If you give people their time back, they will fill it out with whatever they actually want to do, and that's freedom.
Conversely, the erosion of free time over the past generation has arguably also eroded the social structures that keep people healthy.
There's an "epidemic" of people who have nothing to do and for whatever reason can't figure something out
https://www.apa.org/monitor/2019/05/ce-corner-isolation
Retiree data also shows finanical freedom and free time often doesn't lead to people figuring out something to do
A small parallel is that (for me) a weekend is not enough to do much more than recover from the workweek. But two weeks off is enough to recover and then do some more things. Even then, it would take more time to do things of major significance.
Chasing a ball, professionally, for millions of dollars a year, gives some very rich and famous humans a sense of purpose.
Laying on a beach and surfing may fulfill a sense of purpose for other humans.
Some humans need to solve hard problems.
Some humans need to create something original.
And then a lot of humans... most humans... drift through life without any sense of purpose. Does work, the need to work, give them some? I'm not a Calvinist, but I have to live in a world where most people are like that. So if they don't have some need to do something, idle hands are the devil's plaything, and no good can come from the idleness. Just drugs and dissolute degeneracy. Take it from a creative alcoholic who struggles with the question of purpose myself, and finds some light between music, painting, hard work I have to do and my better angels.
That's what you're having a hard time fathoming, because you think everyone is like you; imbued with meaning and purpose that they will find. They are not. Even those of us who are, or were, don't always remain so.
But need? Need wakes you up.
The crush. The urgency. The do or die. The death-defying situation. Sinking or swimming. Here is what brings out the initiative and the creativity and the purpose in people.
I used to believe exactly what you said when I was 17. If we didn't have to work we'd all use our free time to make amazing art and poetry and contribute to humanity.
Look around, man. I know a lot of people who don't have to work. Half of them are homeless and the other half are millionaires. You know what none of them are doing with their free time?? Anything resembling something with a purpose.
Whoever told you this or gave you that impression? It certainly does not reflect anyone in my life. It sounds like symptoms of major depression. But I strongly suspect it is actually just a lie.
What do you think people did before work was invented? Or rather, do you think evolution shaped humans in an environment that demanded 9-5 desk sitting, email sending, backcircling?
It's extremely revealing that people seem to not even be able to come up with things that might give you a sense of purpose in life. No wonder we're all depressed cynics.
Granted, society benefits most from the work of the exceptional, so it may still be worth it.
I also don't believe that we have eroded free time over the last generation. As one example, many now have a robot vacuum cleaner, which frees whatever time they previously spent vacuuming. They may be spending a lot of their time on things, but as long as those are things by choice, it's still free time.
That's a baffling proposition. I think society benefits overwhelmingly more from the sum of average contributions, not the rare exceptional contribution.
I do think we're missing out on a huge number of exceptional contributions due to the circumstances people face who would otherwise be free and able to make such contributions. Instead they are sending emails.
So yeah, even if no one ever really enjoying being a gas station attendant, getting up and going to a job to earn money and pay rent gives people a sense of purpose. And UBI definitely risks robbing people of that purpose. The alternatives to UBI soon though might be creating fake jobs or letting people starve.