Case helppppp
A case with a raised front lip (0.5, 1.0mm or more) and you probably need no screen protector. Any of those cases give that.
A case with no lip? Think about a screen protector. A plastic screen protector is soft and will scratch more easily that the phone's screen. So you will wind up replacing it.
For ANY case without screens just be aware where the screen is or next to. If that little bit of caution is too much worry, get a screen.
LifeProof and Otterbox are a bit too much case unless you are working in a rough job and very clumsy. I only use my LifeProof Fre while fishing in the water or beach stuff.
Apple case is fine, but will get dirty looking fast and probably break if you remove the case every day or week.
Don't rub sand or dirt on screen while cleaning as that WILL scratch screen. Lightly blow it off first. Beware of diamond or zirconia earrings too. Carry a micro fiber cloth and use that to clean the screen. Wash the micro fiber now and then.
If you're a guy with phone in a clean empty front pocket and a case above you're fine. If a women keeping phone in purse with other junk, a screen protector may be advisable.
A phone with no case, dropped, with show damage over time. Just like any thing else.
A case with 1-2 mm of thickness on each side is enough protection for the average person. Of any material.
The exact case is then your personal preface, with the above guidelines, the 'law of averages' are on your side and damage is unlikely.
Spigen makes nice cases. But anything will work. My wife and I have the same case. I have no screens and she does.