The gulf between the Championship and below

Is it getting bigger. Yes I understand that we won yesterday with a 95th minute goal against a league 2 side, however looking at the other results from the cup yesterday, only 1 championship team was beaten by a lower league opposition.

12 won in normal time
2 after extra time
Derby were winning at Grimsby when their game was abandoned.
Preston were the only Championship team to lose to a lower side (Accrington Stanley).

Money obviously plays a big part in this, as barring a handful I can think of off the top of my head, there's few Championship teams now who haven't played in the Premier league.