The taxes thing confuses people mostly because they don't understand how existing phase outs work.
Right now the government pays benefits that are already close to what a UBI would pay, but in food/education/housing/other assistance. Then those benefits aggressively phase out.
The phase outs are crazy. First, they invert what you want from a progressive tax system, because lower income people are paying the highest marginal rates. You might be paying a "10% tax rate" but if you're also losing $0.50 of every dollar to benefits phase outs, your marginal rate in practice is 60%.
Worse, because the benefits phase outs are individual to every program, they overlap randomly to nonsensical effect. Someone making $20,000 might have a marginal rate of 80%, at $24,000 it's 110%, at $28,000 it's down to 40% but at $30,000 its back up to 60%. This is obviously very stupid and creates bad incentives.
Now suppose we align all the phase outs so that a) the phase out rate is uniform across all programs and b) we don't have lower income people paying higher marginal rates than higher income people.
Then you might have something this. Everyone pays a 10% tax rate from $0 to $60,000 and a 30% tax rate after, and benefits phase out at a rate of 20% from $0 to $60,000 and are fully phased out by $60,000.
Well, it turns out this is mathematically equivalent to paying the benefits to everyone unconditionally and having a flat 30% tax rate starting from $0. And if you convert all the benefits to cash instead of food vouchers and such then you have a UBI.
On paper eliminating the phase outs costs a ton of money -- everyone making $60,000 would have to pay $12,000 more in taxes! But then they all receive a $12,000 UBI and it just cancels out.
The primary transfer effect is really in not having such aggressive phase outs, i.e. not putting such high marginal rates on lower income people. The effect is that they have more money, and higher income people have to pay higher taxes to pay for it. But not by the full amount of the UBI, only by the difference between the status quo of aggressive phase outs and the less aggressive ones that make the marginal rate curve not so silly. You end up with a modest transfer from higher income people to lower income people, vs. the status quo.
And then, because lower income people are more likely to spend what they receive than higher income people, you get more consumer demand, which is good for businesses.
You also have a greater incentive to work for lower income people, because they get to keep 70% of what they earn instead of 40% (or -10%).