my bad, I meant to say "rigid" not "rugged".

probably unpopular opinion but Nokia Lumia had awesome design - they use polycarbons so they case wasn't unpleaseant to touch and had this "rubbery" feelings and was not slippery...

The Sony 10 vii that launched yesterday for 450€ has a grippy back according to reviewers, and the Fairphone 6 I've found has plastic as well (battery is removable so the back needs to come off reasonably, not like these horrible two-micron glass panes)

The problem with most of these soft-touch plastics is they are incompletely polymerized and will eventually disintegrate into a sticky mess you need to strip off to get to the hard plastic they are painted on. Silicone doesn't, but it's seldom used as a coating.