You say "nonsense" then proceed to argue in the most bemusing linear manner.
De Gea's errors and limitations in both the games against Sevilla and the final vs City were evident. His limitations also impact the way in which we play, the way the manager wants us to play - so much so he made a u-turn on renewing De Gea and prioritised the GK position.
If you want to stay in denial about how much De Gea affected our play style, as well as key results, with a dash of fanfiction about Kane being obtainable, then please proceed.