If winning as many games as possible in 2025 is your main goal then yes, Carr is your best option. But, I could see a new HC coming in and wanting to reset it all. If so, he might want to find out what he has in Rattler, make the season about developing young players, get higher draft picks in 2026, and then either draft a young QB if Rattler doesn't work out or use the good picks to build around Rattler.
I'm really fine with either option as long as the new HC is the one making the decision.