The west London side was relegated along with Reading after the two played out a 0-0 stalemate at the Madejski Stadium on Sunday afternoon.
Redknapp will now be tasked with building a promotion-winning side for next season but he believes the second tier will prove very difficult going.
"There are massive clubs in that division," he told reporters. "QPR are not a superpower going into the Championship. If you look you'll see several big clubs that have won things over the years."
The Rs boss has previously described a split within the dressing room he inherited at Loftus Road and was disappointed with the manner in which the relegation was confirmed.
"It was a mundane sort of game," he added. "It was as though both teams knew they had gone down.
"There are problems within the club. It's not been an easy club to manage. The balance of the team, in all honesty, was never quite right."
Nigel Adkins, meanwhile, believes the Championship-winning players in the Reading squad will stand the club in good stead for a promotion charge next season.
"We've got eight or nine players who have sampled the Championship before, having won it, so the experience of that puts us in a positive light," the former Southampton boss said.
"Obviously it's a very somber dressing room. What we've got to do is bottle up that feeling and make sure we never feel that again, because it's not a nice one."