Why does that logic not apply to those on higher incomes?
Have a job with a free-market rate of $100/hr? Why not work for only 30 hrs a week?
Also, UBI levels are never proposed at $3k/week ($150k/yr), but rather at about $250/wk ($13k/yr), or only 2-3 hours of work per week for the $100/hr guy.
$3k with tons of free time all week.
Or add working for $3k extra money by giving up all your free time? Not worth it.
Unless of course apartments become $5k a month since that's about the money that a person on UBI plus a bad job has..