Chapman deadline trades have yielded Gleyber Torres and Cole Ragans. Torres has been a decent player but Yankee fans were fine seeing him go. Ragans had a great 2024 but is having a nightmare 2025.
There are no guarantees that trading Chapman would bring back anything that would excite you 2-3 years from now. In return for that chance you're giving up on a season and all the time, money and emotion that's invested in it.