I think the phone looks far better than any case. Just my opinion, but yeah - why cover it up? Just be careful and/or get AC+ in case of accidents.
Personally I don’t care about looks when it comes to a phone, aesthetics are the last thing on my mind.
Why cover it up? It only takes one drop to ruin your $1,000 glass phone. Even if Apple care covers it you still have to go through the hassle of getting it repaired