Letting Alonso go is actually an easy decision if. they invest and have a good plan for the future. They have good player dev and fix Alvarez, etc. His power is pretty nearly irreplaceable, and it plays in a pitcher's park. Pete's been doing this for a long time, Vientos doesn't even have a full season, you simply can't just say "oh go play first and do what you're doing." and think that's enough. You need that home run power. Alonso plays poor defense. He's at 1B. Sure, you could DH him but why lock yourself down there? Plus he doesn't want to. Mets are 6th in run creation this year, 8th in the second half. Not terrible, but not comfortable in the "we hit well enough so we can focus on other holes" game. Alonso's 133 wRC+ in the second half is on par with his career norm. That's 48th of 131 qualified hitters even. He's a good hitter. He's just SO one-dimensional that it does present all sorts of opportunities to replace him. On the other hand, the solution to replace him offensively is simply a money one. You couple simply refuse to be outbid for Soto.