There's no reason to do it as it's designed as a lifetime filter.
I've not done the job on a Subaru, but I swapped the fuel pump out on my daughter's 2002 Taurus. It took me about 3 hours start to finish. I bought only the pump and filter sock so this time included taking the fuel pump basket apart, pulling the old pump, dropping the new one in, and buttoning it back up.
Keep in mind there are lots of variables that could hold you up, such as rusty nuts & bolts. You should run the gas tank as empty as possible so you don't have to fight with a bunch of weight when trying to drop the tank. I don't have a lift so I backed the car onto a set of ramps.