The problem is you have a bunch of yahoos in the press who have no clue about materials science or engineering, commenting as if they were experts in materials science. Speaking as a structural engineer: No, metal is not always better. That's a common misconception held by the public. Each material has a dozen or so properties relevant to a particular application. And for phones, plastic actually ends up the top choice in a lot of important criteria.
We already went through this in the 1940s and 1950s. As cars got faster, more people were dying in accidents. The car makers did the "obvious" thing and started making the car bodies stronger, using more metal. And people kept dying. Then someone decided to do some crash tests to figure out exactly what was going on. Surprise! The stronger car bodies were
contributing to the passenger deaths! In an accident, the car body would hit, and because it was so strong it would immediately stop. The passengers meanwhile would keep going, and became jello when they impacted the dashboard and windshield at full speed. That's when automakers began designing car bodies to flex and give way under impact - modern crumple zones. Except with the lower impact forces felt by a phone, plastic can do that while still reverting back to its original shape after the forces are gone.
With flexible displays just on the horizon, we were on the cusp of getting the perfect phone. One which was flexible enough you could repeatedly slap it against the edge of the table, severely bending it, all without damaging it. No need for a case - you could drop it and it would never break. If the plastic surface gets scuffed up, just replace it with a new $5 back. But the ignoramuses in the press with their misguided obsession with metal bodies have probably pushed that at least 5 more years into the future. Just so they can continue wrapping their precious metal phones in a ridiculously oversized
plastic case to "protect" it.
NOBODY needs that light on the side of their phone (again which sets you back 150EUR!!!!!!!). I have seen several people showing off that functionality today. One guy had the S6 Edge lying 'flat' (not really, thanks to the camera) with its back on the table, fiddling around with the side menu while the screen is off. WHO is going to do that
The edge display was made to address a very real and specific problem. Women carry their phones in their purses. When the phone rings or they get a text, they have to pull out the phone, and flip open the cover before they can decide if it's something important that they need to answer or reply to right now. With the edge display, they can peek at the phone while it's still in their purse, and make that decision without taking it out.
Its functionality is currently being oversold, with a bunch of other marginally useful functions added to it. But its primary function does fill a very real need.