I think curved screen makes sense for this phone. we are comparing this phone with Samsung Galaxy Edge series phones, be it S10 S7 edge.
We should remember that this is a slider phone therefore it has its thickness from the keyboard part too, which rules out the question of accidental touches.
I was just thinking about how would this phone look without a curved screen from the sides, it anyways has thickness more than a typical smartphone (ofcourse ??) (welcome slider keyboard welcome)