Not exactly. There are some odd assumptions in that, and it ignores the offset benefits we would get from innovation, research, and small busi was starts that otherwise cannot exist.
Moreover UBI makes most sense in conjunction with eliminating several other programs that would be rendered redundant by UBI plus eliminating corporate welfare...that last being a really fuzzy number. [prospect.org]
While it sounds great on paper, it has still yet to actually be tested. The Finland test, admittedly very flawed, was also considered a great failure, even by those who were promulgating the idea of UBI. Unfortunately, it's the kind of experiment that could potentially destabilize an entire country if it all goes wrong. And, it doesn't solve the problem of purpose. Humans need both purpose and adversity in order to thrive, grow, and strengthen themselves.