I had a 2017 Mondeo and I loved the interior. Granted, that was in comparison to more modern Ford models but it's actually not a bad place to be. The seats are comfortable and very American/spacious, driving position is nice, it's quiet and there's plenty of storage. Some of the materials aren't the quality of an Audi, for example, but that's a different class (and price) of vehicle in my eyes. The design isn't as bad as you think and actually it's not too fussy compared to a lot of the modern interiors you see now. Properly integrated touchscreen, anyone? That said, high quality of leather and premium it isn't.
Possibly the only bad thing I could say about the Mondeo was that although it handled great, at speed you could tell there were some issues with body control/rigidity of the chassis. However, I can't think of another car that I've ever driven that I would rather do serious miles in. It was that pleasant (with the 2.0L Diesel auto). The boot was also huge which was very convenient. I could take 5 of us to motorsport events and carry all our chairs, food and more with no issue at all. I still miss it now and would have another if I could.