I would suggest you to really examine this myth. I can sit here and say it's bullshit, but I think it would be better as to why you think so lowly of people to think they'd be lazy and "leech." What if they did important work in their lives for no money if they had UBI? Are they leeches? What of a society that disempowers people, that laziness and "doing the least" is a
response caused by other factors? Have you considered how means-testing incentivizes non-striving, and how UBI is one of the few policies to actually break the problem of being "forced into the bottom?"
It's like the welfare queen myth: what you assert is an archetype and you're not really paying attention to the depth nor all of the possible conditions that can give a rise to what you assert. Please delve deeper.
Furthermore,
Guy Standing argues every country can do something with UBI today as a start, and he's probably the most informed person on the concept on this planet, for his fingers have been in every major pilot done of the last 30 years. People call him to supervise the scopes and implementations of the tests we're seeing in California, for example.