Having just been in your situation, I was finally down to a 2019 Rouge SL with 15k miles or a 2020 Altima SV with 16k miles. I bought the Rouge. My experience with Nissan CVT’s has been fantastic, so I don’t worry about that. We still have one in the family with near 140k miles on the original transmission, which spent the first 100 on the highway exclusively.
I considered Fusion 2.5 cars and Toyota Camry (I currently have a 2009 Camry, and a 2000 is still in the family)
The best bang for my buck was the 2 Nissan Vehicles. They were both in the lower $30’s, well above my $20k goal, but not someone’s else’s used up pile. I needed to find a car rather quickly. I’m sure with some time you could find a nicer higher mileage car.