I just think the money that would be needed to sign grealish (fee and wages) can be used much more effectively to target positions we actually need massive improvements in.
Left wing is Ndiayes all day long for me. And KDH is very effective in the no10 and way more dynamic in counter attack transition than Jack. I just don't see where Grealish fits for the money. He's not a squad rotation player and I don't think shifting Ndiaye back to the right to accomodate him is the right move at all.
Money can be better used to sign full backs and striker or a pacey right winger.
I like the guy, but from a footballing perspective, I really think it doesn't make sense