He’d get a substantial amount of minutes here.
He’d be working under one of the best coaches in Europe.
He’d be playing in the Champions League.
He’d be playing with a significant number of current/former England players (Burn, Trippier, Gordon, Hall, Livramento, Pope, Trafford(?), Guehi(?))
If he wants to become the best player he can be, we’re the best option out of that list, as it currently stands.