It's entirely managerial. The talent is there if utilised properly. But that's not going to happen with a guy in charge who failed at Middlesbrough.
----------------------Butland-----------------------
--------Jones-------Keane--------Stones------
Walker-------Dier----------Winks---------Rose
----------------Dele--------Rashford-------------
-----------------------Kane--------------------------
Subs - Pickford, Cahill, Bertrand, Barkley, Lallana, Sterling, Welbeck
If that side had a manager like say Thomas Tuchel, who is out of work, in charge at next years World Cup we'd have a chance. The bench is rather weak though along with the defence.
When you have someone like Southgate playing wingers as number 10's (Sterling) and centre forwards (Rashford) and central midfielders (Oxlade-Chamberlain) on the wing, you're fucked.
I agree that Southgate is a shit choice, as you point out his track record is shit. Same with Hodgson and others, failures who get rewarded with the big job. It's stupid. But I think we are lacking in talent in important areas. Our goalkeeper is not great, our central defense is not great and we lack creativity. The only players who are up to it as Spurs, ex-Spurs, and Rashford.