Toyota doesn't even list the fuel filter as needing to be replaced up to the 120,000 mile severe service
Strange, do you have a copy of that? Hopfully you car doesn't stop running when you reach 100,000. I thought you said you never have to change the fuel filter. I'm confused!!
Some dealers state you need to change fuel filter at 60,000 and some say 80,000. In my opinion 60,000 is to soon and 80,000 sounds right. When I took my fuel filter out at 80,000 it was bad, very bad in fact. It was filled with dirt, that easily came out when I tipped the fuel filter upside down. Do you know where all that goes? To your motor. If I drove 40,000 miles more, can you imagine how dirty the gas is going into my motor.
Toyota will put 120,000 in the manual, so that they will see you pull in the dealer wondering why your car will not run.
Changing your fuel filter is routine maintenance regardless what car you drive. There is no filter in the world that last forever. Severe means, "very bad" so change before 120,000 miles.