i would have had a lot more respect for him if he had resigned with the Yankees.
meh, I don't see him as gaining or losing cred for signing or turning down the NYY. He was a rental at that point. he was destined to test the market from 2022 on.
He only played 2018 with Harper and was destined to be his replacement. I am skeptical that letting Harper walk after Soto's rookie season was the writing on the wall, although IIRC he didn't move to Boras's organization until after that season. Had they re-signed Turner (and had Kieboom panned out), I think he would have been comfortable thinking the team was willing to commit to contending.
In retrospect, maybe the defining on-field moment for the fate of the franchise after the WS was 7/21. Stras's injury knocking him out for the season, Corbin blowing up after a decent 2.5 month stretch from mid-April to end of June, and Schwarber's injury led to that tailspin from above-.500 and a couple games of the division lead to "let's break up the team for what we can get" sell-off, which I think doomed re-signing Soto.