It’s a screen that can crack scratch and or chip. That’s up to you. ALOT of people buy these $1000 phones but don’t use cases. I like to protect my purchases ESPECIALLY expensive ones. A screen protector yeah will effect the screen quality (very little) but I’d rather be protected for less then $10 then having to pay $100 to change a screen that I could have prevented. I personally prefer the tempered glass screen protectors rather then the thin film ones.

To offer a contrary opinion, I’d say not at all necessary on the Deck. You aren’t putting in a pocket with keys or something like you might a phone. You aren’t laying it face down on the screen like you might a phone, because the sticks would get in the way. If you’re throwing it in a bag, you’d be nuts to do without a protective case or cover, and if something is still enough to damage the screen a screen protector isn’t going to save you. If you drop it, it’s going to take more severe damage to things like the sticks, triggers, bumpers, etc. before it ever touches the screen. If it’s a rough enough fall to actually cause screen damage, the screen is the least of your worries. It’s probably dead at that point.

depends on your lifestyle and the kind of person you are. i don’t have a screen protector on anything i own and never had an issue. i don’t share my stuff or have people in my apartment touch my things. and i only play it indoors