My fear about UBI over the long term is that it will just get baked into prices

That’s why UBI alone would ultimately not help much, but UBI and price controls would be EXTREMELY helpful, especially to those struggling the most.

money dropped out of the sky

This is basically what most money is already. Difference with UBI is that a certain amount is guaranteed to go to everyone to create a financial floor, rather than almost all of it going to the 10% that exploit the other 90%

who’s to say that anything fundamental in society will change?

With UBI and price controls combined? Unless the UBI amount is too small or the price controls are too lax, it literally can’t NOT fundamentally change a society where the majority is struggling to get by.

All the basic supplies and demands will still be there

Except there’s TONS of market forces beyond just the basics, including ones that artificially deflate income and inflate prices. UBI combined with price controls would undoubtedly change the entire landscape for the better for the struggling majority as well as those of the rich whose income is at all connected to open commerce rather than just the stock market casino.

Anyway, you shouldn’t expect a government to go STRAIGHT to UBI without some shorter term one-time stimulus experiments

Except for the fact that such incrementalism has been shown again and again to take one or two insufficient steps in the right direction before being rolled back by opposing forces.

When it comes to transformative change, half or quarter measures and onetime tests just don’t work.