It’s like we can’t have good phones. If you want Headphone Jack, SD card, Message LED, and synthetic back, you can’t get a phone with good camera, GPU and water resistance at the same time.

Why are phone makers so hostile to their own users?

Another thing is that now they make “vegan leather” as the new “premium feel”, which of course won’t break like glass, but it still doesn’t have nearly the durability of a decent synthetic/plastic back, which IMO feels great to hold and makes the phone lighter and despite being better it’s cheaper.

With the glass you get extra weight, and with a cover, you get extra bulk and weight on top of that.
It’s drives me nuts how insane this design decision to use glass is! Vegan Leather isn’t that much better, I had the LG G4 with leather back, and it got pretty ugly after a couple of years. But at least that could be easily changed/swapped by the user. And according to every source I can find, vegan leather has lower durability than real leather.

Glass backs are the dumbest idea in the history of stupid.

The only way things like that could be defensible if they were easy to replace (bring back Moto-Z style magnetic backs!), but since phones are all held together with glue now, that’s not a thing.

Glass back is a premium design feature because it breaks easily, and customers who buy premium phones are expected to be rich enough to just buy another phone.

It’s a profit making feature.

Much like luxury cars, nobody actually expects BMW or Mercedes to last more than 3 years. People who buy them are expected to trade up for the latest model every few years.

Same with luxury fashion. Absolutely some of the cheapest and fragile clothing I’ve ever seen come from big fashion brands. And nobody cares, because by the time they break, they’re out of style and the buyer will be updating their wardrobe anyways.

If there’s one thing I’ve learned, expensive luxury items = cheap and breakable. Midrange products are where the customers tend to be concerned with longevity and value.

Searching in google

why do phones have glass backs And all the top results explain why in a single sentence: wireless charging.

You can’t have wireless charging with metal backplates, hence the glass, which is often not your ordinary glass but things like gorilla glass which is much harder to crack.

I know it still sucks; I have an iPhone 12 that was still in great condition after 4yrs, never used a case on it; but one day at the pool of my son recording a video and dropping it just right cracked the back. I just stuck a dbrand sticker onto the back to hold the glass in place and it continues to work without issue!

A few years ago my wife left her caseless Samsung S7 Active on the top of her car & took off with it still up there. Fell off the roof while she was doing highway speeds. She actually managed to back track to find her phone just in time to watch a box truck run straight over it.

It still worked fine. Gained a single scratch.

I wonder why glass back is so popular,

They are being hyped up by marketing because people easily fall for it. Even you:

Then I bought my $800 glass back Xiaomi 13T Pro in January

It works the same as with cigarettes: people think it’s cool. Most don’t care about the rest. Easy money for the suppliers.

Good for you for calling them out on their bullshit. Anyone else with a history of dropping their phones from their pockets (and yet buying a flashy glass back (and refusing to protect it with a case (and referring to it as a condom))) will benefit from reading about your awakening and they might go for something different.

Just remember, if you fell for this one, you might fall for another marketing gimmick unless you pay more attention.

PS: I don’t use condoms for my phones, if they need that for daily use, it’s an obvious design flaw!!!

You don't use a condom because you know you'll get a girl pregnant, you do it on the slim possibility. There's always going to be outliers, and refusing to prepare for the possibility because it's remote is playing with fire. It's asking for a worst case scenario when the preventative measures are so very easy out of pure arrogant principle.