There are good reasons. Firstly he isn't the only road to a good draft hand. Secondly, who says we won't challenge? He's 25. He'll be a gun until he's 35. Experienced classy players are part of the contention equation. If we rebuild well and are on the up in 3 or 4 years, we could be looking to trade for a Shai.
I'll say it again, if we had no picks and no other currency, and he was 28, you'd have a strong case. As it stands, sure you can make the argument to trade him, thats fair enough, but anyone who disagrees is not conservative or small minded or short-sighted or whatever, that is gaslighting BS.