A player knowing that he is buried on a team's depth chart and/or being constantly recruited over can transfer at any time and get some instant playing time is what is driving the NIL money quest.
Riley Leonard, as one example, may still have left Duke but he may be incentivized to go to place that needs him to fill a hole/gap in recruiting that gives him a better chance at team and personal success.
In many cases, this leads to "second tier" teams being able to enhance their talent and become more competitive with the top tier teams. The collar hypothesis leads to underrecruited/ late blossoming guys also getting the opportunity to go from second tier teams to top tier teams and enhance their long-term earning potential.