I'm living in Eastern Europe, where, although no "basic income" was introduced, the changes in the last few decades led to a situation similar to basic income

Well, this is one point of view obviously, but UBI supporters might disagree about how "similar" it is. Some of the things you mention, wrt. family farms being abandoned in favor of urban lifestyles, are happening literally across the world; the unfavorable comparison with the West is also not something that basic income could affect either way. And ISTM that widespread abuse of things like disability is even worse than most 'welfare' in making people disinclined to work. But this is something that UBI aims to correct, while still making life easier for the folks who receive it.