The Lionesses were knocked out in the semi-final on Thursday after losing 2-1 to Japan.
Sampson, who refused to confirm whether he would remain as coach after the tournament, said England still have plenty of catching up to do to become a world force.
He told Sky Sports News HQ: “The challenge not just for this team but the England women’s football community is how to build on this.
“Let’s not forget women’s football around the globe is catching on, a lot of nations are investing a lot of money.
“We’re still playing catch up with them. We’ve got to raise the bar and give this national team a chance to come back as winners.
“We nearly got there this year. We’ve got to get more girls playing the game, have more centres so they can play and experience. It’s a long way to go, but this has been a big step up in the gears.”
Sampson’s side must now focus on their third-fourth play-off game with Germany on Saturday.
But the coach is undecided on whether he will stay in the job after the tournament in Canada.
He added: “I’m a football coach and I can’t wait to coach my next game. After this tournament everyone will have to go and reflect.
“I woke up this morning and couldn’t wait to say to my staff I’ve got a plan against Germany.”
Sampson insisted the team have rallied around Laura Bassett, scorer of an own goal in the 90th minute which saw England knocked out.
“Laura has been up with the team, it’s difficult for all the players. It was an emotional night and the team rallied round her.
“Her family were amazing yesterday in really helping her through and she went to bed in a far better place.
“She is a model pro doing her stretching and recovery today and helping this team move forward.”