Taxation and inflation are 2nd order effects. There's a deeper underlying reason.
The point of work is to produce the things we need to live. Somebody's gotta grow the crops, drive the trucks, mop the floors, crunch the numbers, process the paperwork, write the code, whatever.
If you offer enough UBI for people to live without working... the work won't get done, and things we need won't get made.
Has anyone ever tried to look at the concept of a Universal Basic Job? If you can show up semi-sober, you get paid to paint over graffiti, or pick up trash along the road, or something.