> simply from cost of goods dropping so low that buying the basics to live will be so cheap that you don't need much money to begin with

Basic income gives you not just money, but time. If you receive basic income, you can work less. If people live in a culture where everyone must remain in full-time employment until age 65+ and the vacation time they are allotted is meagre (e.g. the North American situation), then it is cold comfort if the money they make allows them to buy basics for more cheaply.

Secondly, while the basics of food or clothing have become cheaper in developed countries (though often only if you are comfortable sacrificing some quality of the product), housing prices are soaring. While a basic income, too, would have a problematic interaction with housing prices, housing costs would remain an issue even in the alternative future you posit.

Sure, because rent will just get cheaper and cheaper, as we magically make more land and nice housing appear, then give it away.

Do you have actual numbers on this assertion? Preferably scaled to population?

I don't have the numbers. You would need to go to the history books to find it but you can see the trend in action to a certain extent for certain occupations. A prime example is farming. In aggregate, total employment in farming has declined significantly. The people that are left are doing higher level work, not tilling the field with a donkey and plow, they're driving a tractor or doing soil analysis etc. The field laborers moved to cities and now they do light manufacturing or similar jobs with maybe a few weeks of training.