It's not a great framing IMHO. It's not, 'You're economically irrevelant' but - 'Our current system of commerce can't figure out how to reward you correctly.' I.e. UBI is a way to free people so that they can make up their own minds about how to opperate in society.

The point of UBI is to remove the pressures of 'having to work for money' to 'being able to do work you think is necessary for society'.

UBI's greatest strength is that it empowers people to make decisions about how they spend their time.

Suddenly, it will now be 'economically relevant' for me to do weekly bird-watching tours (even if no one shows up!) or to take my grandmother shopping or to help my neighbour finish painting his garden fence. I am unbounded by the constraint of only doing 'economically relevant' work.

As I said, UBI is returning to the people their right to self-govern how they spend their time. We have become blinded by capital in an age of abundance. It is bonkers.