Well, given that UBI studies have been promising so far (despite their limitations), there seems to be a decent chance that quite a lot of multi-generational poverty is primarily caused by... multi-generational poverty, meaning it's a self-reinforcing cycle that's difficult for people to escape. Or in other words: when you're broke, it's really hard to build wealth, so you're likely to stay broke.

Perhaps it's an over-simplification, or perhaps a lot of people have been over-complicating the problem, particularly when they're trying to prop up a pet political bias.

If we implement UBI on a large scale and it drastically increases upward mobility, I suppose this hypothesis will be more or less proven. I hope that day comes sooner rather than later so we can find out.