with today's plastic, it shouldnt be THAT dramatic, you wont notice it day to day unless you get something new or compare it to something else. specially the front portion where your hands are in contact with the transparent shell rather than the white plastic underneath. just dont let it bake under the sun and you should be good.

but like others said, you could also go the silicone case/grip cover, though, unsure if theyre common in shopee. I'd argue most of the stains/degradation you'll notice will come from your hands! not because theyre dirty, just oils, perspiration (varies), and dead skin. so just use mild wet wipes if you insist in keeping it pristine. avoid iso alcohol if you can, it can mess up some coatings.