Hello, I'm not that informed about UBI, but here is my arguement:
Everyone gets some sort of income, but wouldn't companies just subside the income by raising their prices? Also, do you believe capatilism can co-exist with UBI?
Its not like UBI invented competition. The fact that prices are rising for goods while costs to produce said goods is lowering is a symptom of lacking competition and a broken system.
At some points big companies are just going to agree to stop lowering prices. There's a reason insulin is so damn expensive.