iPhone Xr falling off flat surfaces.

I replied to another post, but I want to get more in detail with this one. I've had my iPhone Xr since Friday. Today is Monday. Without even leaving the house, the iPhone has FLUNG itself on to the floor (it's very dramatic) several times. I thought I must have been crazy, maybe I wasn't paying attention, maybe I was playing music too loud, but this morning I paid VERY CLOSE attention, and it did it again. Let me show you the surface it fell off of:

It is a flat, level surface, a small cabinet in my bathroom. This is where I set the phone when I got into the shower this morning. It's face up, has no case, is not playing anything. You can see that it is fully on the surface. There is more than an INCH of clearance before the edge.

When I started washing my hair, here is where the iPhone had jumped to:

AFTER I heard it go thud, and was already cursing out loud, THEN I heard the *ding* of an incoming DM.

Now. I had no intention of putting a case on this phone. Why TF would I wait a week to get the red version if I'm going to put some dumb case on top of it? Why make them in colors at all? YES it survived the fall (the color on the edge CHIPPED!!), but WHYYYY?