because it breaks when you drop it? it provides a gripped texture so that it's easier to hold on to?

If we're talking about iPhones, they don't necessarily break when you drop it, especially the last few generations. You might get an unsightly scuff on the back or edge, at worst the back glass might crack — but it will do so in such a way that the phone still won't shatter.

In fact, my partner's iPhone and my previous one both broke in independent incidents when both were in cases. My new phone, I don't use a case, drop it regularly on asphalt, concrete, and it's even taken a dive into hot dishwashing water — and it's just fine.

I know somebody will come along with a story about how theirs smashed into smithereens but, for my money, Apple builds their phones to last.

> at worst the back glass might crack

this isn't broken??

Technically, yes. Realistically, no, because it's not the sort of crack that will make the back shatter; the crack is, somehow, under the surface glass. On my phone, it's entirely cosmetic — it knocks the resale value down, but that's about it.

Fun fact: my phone took its dive after the crack. No water got in at all.

Calling it a crack when it's made with crack-resistant glass doesn't give the right impression of how undamaged it really is, compared to one's expectation that it shattered into a million pieces and embedded itself into my carpet like grenade shrapnel — it ain't like that.