Ratcliffe and his Ineos management team bought a minority stake in United almost 15 months ago. Since then, United have seen a manager, Erik ten Hag, sacked, 100s of staff lay-offs and the team languishing in the bottom half of the Premier League table.
But Ratcliffe told BBC Sport: "We are roughly where we thought we would be, but it's also been quite challenging because there's been a lot to do, and quite a lot of issues in the club we've needed to resolve.
"Regretted the transaction? No. Not at all. I didn't expect it to be a walk in the park. It's quite tough sometimes reading the press, obviously. But in a way I'd rather the press had a go at me than Ruben (Amorim) the coach.
"You know I suppose I've stood out there and said 'we can make Manchester United great again' so people are entitled to their opinions. In my view are on the trajectory I thought we would be on. We are in the process of change at the moment.
"We put a new management team in place. We didn't get that all right at the beginning, obviously. But today I think we have a really good management team in place.
"We are dealing with the financial issues in the club, because the club has got financial issues and we need to address those. Then we need to move on to the squad, recruitment, data analysis and those types of things. So we are on the path we anticipated we would be on."
Asked about the protests that were staged before Sunday's 1-1 draw with Arsenal at Old Trafford, Ratcliffe insists he understands the frustration.
"Yes and I sympathise with them because Manchester United is not where it's expected to be. We are expected to be winning the Premier League and challenging for the Champions League and we are not there at the moment. But I think we need to get the house back in order before we can get back to our winning ways."
He then took aim at past signings.
"That's the process it takes. It's not a light switch. I'll give you an example, if you look at the players we are buying this summer, that we didn't buy, we are buying Antony, we are buying Casemiro, we are buying Andre Onana, we are buying Rasmus Hojlund, we are buying Jadon Sancho.
"These are all things from the past but whether we like it or not we have inherited those things and we have to sort it out. For Sancho, who obviously now plays for Chelsea, and we pay half his wages, we are paying £17m to buy him in the summer. So it takes time for us to move away from the past into a new place in the future."
Put to him that many fans now see him and Ineos as part of the problems engulfing United, Ratcliffe conceded some "errors" had been made.
"We are not perfect, and we are on a journey, and there have been a couple of errors along the way, but I think in the main all the things we are doing are the right things for the club. And the club's going to finish up in a very, very different place in three years' time to where its been in the past, in my view.
"I think it will become the most profitable club in the world. In three years' time Manchester United will be. That will be my prediction for Manchester United - it will be the most profitable club in the world. I think we may well finish up with the most iconic football stadium in the world, and I think we will finish up winning silverware again."