Could you elaborate on how would one sustain themselves without UBI in the US (according who those here who would say the same)?

Things that I typically read:

- the lower class struggle even to sustain themselves for days/weeks in between jobs

- in the middle class there is people who fear not having health insurance in between jobs

How can one survive in US without any job at all? US's welfare is radically different from Denmark's.

The US has many fragmented welfare systems, rather than a single universal system. Many people do live on a combination of these benefit programs. This does not mean they do not struggle.

People who are out of work for short periods of time may not be familiar with all of the various programs and how to sign up for them, and it may take some time to do so. They may also have budgeted their expenses with their employment income in mind. This is why things are particularly difficult for people who intermittently lose their jobs.

But in general, anyone who finds their income unexpectedly unstable or close to the minimum amount necessary to meet their expenses will have a tough time, no matter where that income is coming from, or what value it is.