the catastrophic (ie working a 9-5 job for life) risk now.
Being able to improve draft stock and be more ready to get minutes in the NBA (and thereby sticking in the NBA and getting that second contract) is much much more important to long term success than simply getting that first NBA check, because you already got NIL checks.
Putting cart before the horse for a short term gain sometimes works but more often doesn’t. The NBA doesn’t have a great track record of developing players that sit in the bench.