I really doubt its the fuel filter, it sounds to me like a poor fuel/air ratio. For reference, you usually get 100-120k out of O2 sensors and 200k out of cats. And only use MAF cleaner for that, any other cleaner risks damaging it. If you suspect the fuel filter, an easy test is remove it, and let the fuel pour out of the inlet, if it's anything but clear then that's not great, and then blow through the filter once most of the fuel is out of it. Blowing through it shouldn't be that difficult but you'll know when it's clogged.
As far as mileage goes, that's a good bit but I'm guessing you won't be able to find out if/when some of the sensors were replaced.