NO went 20-8 to finish the season last year without Cousins, with AD going 31/12 and 3+ blocks.
How is Davis taking that team anywhere? He's got Holiday and not much else. Maybe a more ball dominant player like Lebron could drag that team to an 8th seed, but there's no level that AD could play at to improve that team much.
It's foolish to downgrade how amazing of a player he is. But by the same token, it would be foolish of Ainge to give up a lot for him if he's not totally convinced that he'll resign. And by a lot I mean Jayson Tatum, because that's what NO wants. They didn't say no to LA's offer just out of spite, they said no because they don't want the Lakers detritus of Ingram, Ball, etc., they want Tatum.