I adore Xiaomi's build quality (especially Redmi 4x's metal case and liked the haptics on 11 lite 5g), they are the only cheap devices with decent specs (good SDM CPUs, IR-reciever, now discontinued sdcard slots, bootloader unlocking (for LineageOS with decent privacy (and DivestOS when it still existed)), decent durability and modularity (I ocasionaly repair phones).

**But of course this is just too good to be true, so let's just start with the drawbacks: **

My first personal experience with Xiaomi was the mi 11 lite 5G, which I got as a Christmas gift in 2021. It was the best phone I ever had (both on paper and my subjective perception). Well, let's just say, that perception changed not much after the waranty; first I started experiencing random reboots and after a few months the serious issues started appearing (random connectivity problems). I tried to reflash it and it had no effect. Later all the issues started to rapidly escalate: WiFi now only works if the phone is in warm climate and it resets every couple of minutes (so it's practically useless - so I rob it for parts). Later I inherited my dad's Redmi 4x (don't worry, he isn't dead, just upgraded) and it's also starting to have this issue (after 8 years not 2). I have also seen this problem on many Xiaomis from my friends.

So in conclusion: Xiaomi purchases are a gamble. (at least if you keep a phone for a long time). But they are still the only decent low-midrange phone brand (I even recommended a Poco to my cousin)

Problem explanation:
I think the problem is mostly caused by heat (from the SOC and/or the enviroment) which causes the connections on the CPU to deform and slowly lose conectivity, making the device's core functions slowly deteriorate and Xiaomi didn't fix this problem for years, as they probably don't care.

Solution (probably repairshop):

edit: this is aparently bullshit

The solution to this problem is CPU reballing (a process, where you remove the CPU from the motherboard and replace it's solder. This is not an amateur job, it requires professional tools (your grandpa's old soldering iron won't do).

And of course: I would be happy if anyone would recommend a comparable brand (with at least pricing and custom roms).

My current Xiaomi 13T would be illegal if the new proposed EU regulation goes through.
I dropped it from about about 40 cm because it fell out of my pocket while sitting in a chair. And it instantly cracked the back glass. It was 4 months old and had never been dropped before.
New EU regulation if it goes through will require the phone can endure a drop of 1½ meter on concrete.

However the HyperOS is very good IMO, Xiaomi used to be criticized a lot for their OS, and I hated MIUI, but although HyperOS looks near identical to MIUI, the feeling when using it is just so much better.
So despite the cracked back, I'm actually pretty happy with it.

Wow, you are capable of not droping a phone for four months? I drop mine monthly (I have harmed 2 phones doing this).

I basically never drop my phone. The few times it has happened with previous phones, they fell out of my pocket when getting in or out of the car. After the drop cracked the glass I put a the "glove" on it that comes with the phone, and I haven't dropped it since. That was over a year ago.

The fact that I so rarely drop my phone, was the reason I even bought the friggin glass back version. I inquired about repair, and was told about $300 USD. I don't want that, although the phone cost twice that, it's not worth spending that kind of money repairing a used phone.

I stopped using covers more than 10 years ago, and I've never broken a phone before.
The difference between us is probably in how we use our phones, you may be more active in other tasks while using your phone than me. I only at most do very simple things at the same time I use my phone.

Anyways it's now about 16 months, and 1 drop out of my pant pocket while sitting in a chair on the terrace. The friction of the glove I have on it, helps prevents it from dropping from my pant pocket when sitting in low chairs.

Just buy a back panel from aliexpress for~5€ and replace it yourself.