United have not won the top-flight since legendary boss Sir Alex Ferguson bowed out in 2013.
Asked if United could mirror Liverpool's title drought, Giggs replied: "Yes, 100 per cent. It could be 15, 20 years before you know it, especially if (Jurgen) Klopp and (Pep) Guardiola stick around.
"They have got the resources and the players so we have Liverpool to look at where the last time when they won it in 1990 they thought we'll win it again soon.
"Even Klopp took four and a half years for him to win it - it takes a long time. You have to think about what Klopp did.
"He improved the team every season or won a trophy like the Champions League and then you saw the improvement so the pressure was off a little bit.
"Every manager and signing is seen as that he will win us the league and it's not like that."
The United legend is adamant Liverpool remain their major rivals.
Giggs, speaking on the Greatest Game Podcast, said: "The best feeling I always had was leaving Anfield after winning even if Liverpool weren't the best side at the time.
"I played for Salford boys and our toughest games were always against Bootle, Liverpool, Kirkby, Sefton.
"As soon as you went down the East Lancs it was a mindset it's going to be a tough game and a test of not just your footballing ability but also your mental strength."