You need hard money before you attempt this.
Plenty of nation-states make different trade offs between productivity or growth or whatever and mitigating poverty. To act as if the particular style we have in America is the only possible thing that works is asinine.
You can do either in a hard currency system.
All of the UBI supporters need to do the math on it, it's 'extremely expensive'.
The 'economic collapse' part happens when 'not working' becomes normative, and socially acceptable - and be assured that it will.
The idea of 'working for a living' when you can just 'do whatever you want' is a bit glib. I suggest the only reason people would work, is to pay for that 'special thing' they want aka 'trip' or 'iphone'.
The ideological problem with UBI is the same as any broad social welfare program and that it doesn't reward material output. That is 'extremely bad'.
Finally - I do suggest that it may be possible to 'very simplistically means tested welfare' for people (to get rid of overhead) - and - to allow some of those people to have jobs so they don't get caught in that trap.
In fact, I suggest for people 65+ we'll need a program like this because they can still work, and frankly, working may be very good for their health, and they can do things that are 'extremely needed' right now, such as help to take care of the very elderly.