To be fair to the mainline AS FAs, the website currently specifies that beverages in F are offered on flights over 350 miles so perhaps more of the mainline FAs are actually following the service standard for mainline which isn't always the same as QX since QX Q400 flights offer juice or water for the entire cabin on PDX-SEA flights.
https://www.alaskaair.com/content/tr...food-and-drink