I hate that people lump all models of a brand together. Yes, 40 years ago you could say all Yugo's are junk but that has mostly changed. Some of the least reliable brands as a whole, still have certain models that are reliable and the most reliable brands as a whole, still have certain models that are unreliable. Even someone like Jeep, who overall is bad, makes a couple of models that are somewhat decent.
Also, everyone rates reliability differently. Some studies will put equal weight to cars with transmission issues as those that have bad Bluetooth.
Also, what's been reliable in the past doesn't mean the new model will retain that reliability. Of course a 2021 Toyota 4Runner is going to be reliable, you're basically driving an SUV that hasn't changed in a decade. Does that mean the 4Runner is the best in the class, for 95% of the public, the answer would be no. Give it 2-3 years after a remodel and you'll almost always come out ahead. Reliability is important but it's not everything, especially in today's world where most everything out there is pretty good and so many share components. Think ZF8 Transmission, which I think I have had in everything from a BMW 2 series coupe to a Dodge pickup.
A big question mark with Volvo is what it's going to be like to own a gas model from a carmaker that has pretty much said that every redesign after 2025 is going to be electric only. There are similar questions with other auto makers but Volvo is ahead of most of the others.
As far as the S90, I was given one as a loaner about 5 years ago and I hated everything about it. It's probably been redesigned and a lot better. More recently, I drove the XC90 and it was nice. The one big thing you're doing right is looking at an uncommon large luxury car. These are usually lease returns, well taken care of, long warranties, and can be had at bargain basement prices. I did this in 2013 with an CPO Infiniti M56. A car with an $72k sticker, less than 30k miles, and sold to me CPO'd for less than $36k. When I compared it to new 2013 models for $36k, it was almost laughable.