This is all still a race for 2nd place and it always will be. I think Haley finishes 2nd here and in NH, but as long as Rob and Tim remain in the race, the chances she can overtake Trump are slim to none.
It seems to me that there is inherent value in finishing 2nd in this Republican primary.
What if Trump has wrapped up the nomination at the same time he in convicted in the Jan. 6 trial and thrown in federal prison?
Regardless of the delegate count, I cannot believe the Republican party would nominate a candidate who will literally be in jail for the entire campaign.
In this event, it seems most likely they would turn to the candidate who finished 2nd in the primary. So it's worth it to stay in the race even if you know you can't win, just in case Trump is forced to drop out.
That person would have a negative mandate of being rejected by most Republican primary voters, someone who didn't run would arguably have a better claim to the support of a majority of the party.