I used to not run cases or screen protectors, and my last iPhone had like shit load of scratches on it from regular use , I don’t put it with anything in my pocket and always clean my pocket , also the oleophobic coating on the screen is completely gone and finger prints are horrible now they don’t get wiped away easily , I recommend going caseless but the screen protector no , if you replace your phone every year or two then fine go without it but if you are like me and upgrade when the phone isn’t doing what you want then I don’t recommend it as when the coating wears off it’s a horrible experience and smudges and fingerprints seem to be stuck on their for ever