There's a massive gap between wanting something and doing what it takes to get it. If you were to ask people vs. watch what they do, you'll see the truth; it's never about what people say but instead what they do.
And I'd welcome any supporting research demonstrating that, based off their actions, "most people want to do more than just get by" as stated. My anecdotal observation is that most of (working age) society actually does just enough to get by for today, this week, or maybe the month...
If that's not done, then UBI would encourage migration from higher cost-of-living areas to lower cost-of-living areas. That might not be a terrible outcome; it would probably lead to balancing the cost-of-living across regions as the populations change.
Not average. It's Basic. It's just enough to get by. That's the incentive to work: most people want to do more than just get by. Anyone who doesn't want that would be a drag on any system, so that's a separate problem to deal with. But there are a lot of people who can't get ahead with the current system who would do better in a UBI system, and we'd all be better off if we could get those people productive and happy.