For me it's the loss of the criminally underrated O'Hare
+
The loss of all the key experience in the playing and non-playing staff (Kelly, Fadz, Godden, O'Hare, Viveash etc.)
We had a real identity and standards/resilience expected within the squad, and that has seemingly gone now. I actually think we should have kept Kelly for his role in the squad considering the other changes we knew were going to come.
Still have complete faith in Robins to rebuild it but it's a big job...