Looking at that page is strange:
The year 2017 was rated 8.0.
The year 2018 was evaluated with 7.8.
The year 2019 was evaluated with 6.7.
What changed? Very little. 2018-2019 was not even a year of refreshment.
2020 is said to be positive for fuel economy.
2023 is said to be a negative in fuel economy.
What changed? Very little. They’re both rated 26 city and the 2023 is rated 1 mpg less on the highway.
I’m not sure I understand the measurements used on the site or the lack of consistency as they are measured.
For Outback, I think SilverOnyx has the best guess.
Now there are many other great options with AWD, good mpg, good room, car-like handling, safety features, etc, often for less money than an Outback.
I recently drove a Mazda MX-5 and was impressed with just about everything about it. Too small for my needs, but a great all arounder.