Milan spent €200m last summer on the squad.
“I have absolutely no idea when Milan will become great again, but it doesn't look very promising with this new project for now, so unfortunately we'll be waiting a long time," Maldini told Radio 24.
“This all started under Berlusconi, so it's not just a problem caused by the new directors. The problem is the further you are away from the top, the more years it'll take to get there.
“The winning mentality and aura they had has been lost along the way and investment has to be doubled every year to make up for it.
“In my view, five years ago, Milan were there among the top five clubs in Europe. They have slowly dropped and the investments that should've been made then are now 10 times more."