Yes, it creates a disincentive to work. The hope is that it creates much less disincentive to work relative to a means tested program. I don't think the structural economic advantages are enough of a reason to implement a BI (you have to start looking at fairness issues).

Typical proposed implementations just increase taxes at higher income levels. So there is a taper starting somewhere above the basic income where people that are working are benefiting less than people who aren't working, and there is some income level where the basic income is effectively a pure cost. But all those people have a higher effective income than they would have from the BI.

And it likely would represent a massive increase in spending for most countries, even if it was more efficient than welfare programs. Especially if you make payments outside the tax code, which ends up with a lot of spending that is just accounting.