I don't use any phone until it has a screen protector and case. Don't care how awesome any company claims their glass is, it will scratch under the right (wrong?) conditions.
Unfortunately 98% off all screenprotectors for the S8/S8+ are just 110% crap. I have read only bad reviews about several screenprotectors. The internet is full of it. Probally due to the edges of the phone.
A lot of people already spend like 40 or 50 bucks on screenprotectors which they threw in the bin haha
There is one, also mentioned here earlier in this topic. Will cost you about $50/60, its a liquid glas thingy with UV. It gets some good reviews but its qiuit a tough job to apply