When I watch reviews on YouTube or read comments on Amazon, the main points discussed there are very often things like "the battery is drained after watching 3 hours of Netflix" or "the display resolution is so 2014 / the display is too small" or "the front camera does not take good selfies", etc. I do not care about such things.
I currently have the Blackberry Key2 in mind, but I am put off a bit by the price.
Basically, what I am looking for is a smartphone variant of a classic Thinkpad.
For the most part you can definitely find what you want with an older-gen iphone, or the new SE.
Unfortunately mobile systems have now consolidated to only iOS and Android, and many android phones don't get regular updates / get much slower within 1 year / aren't supported long and even not expected to have a long life by their manufacturers. OTOH lots of people hold on to their iphones for a really long time because they just work, and for many years. Notice how many people still hold the original SE or the 7.
I started consider do buy some older phone for daily driver, and keep the current one for photos/social media/GPS without the sim card even, so as a toy, but I'm still not sure - will happily listen what other HNers have to say here.
The other option might be to wait for Surface Duo till the end of the year, but I think it will be way more pricy than Blackberries..
Surprisingly the build quality is good and battery life is amazing. You can have dual SIM or a SIM and extra memory card. It is not a great phone for gaming or photography, but that's not what you are looking for.
Now assuming the batteries decay over time, screens break and phones fall into the toilet or getting stolen you can buy 2 Redmi's for the price of one iPhone SE.
On Android you can have a full blown Linux Terminal, because Android is Linux underneath.
Termux works without rooting. You can set up a Debian CLI environment using proot on termux and let it run on startup by editing startup file. There are tutorials to run X / Wayland without rooting too. Admittedly I haven't found a need for that so far but that's possible.
Or instead of using Debian environment, you can use vanilla termux environment and have access to Android API if you want. Even then you can still have a Debian / Ubuntu CLI environment
On iOS you can't install different browsers either. On Android you can install Firefox for Android and it supports uBlock Origin.
You can change KeyBoard app and there are many options to choose from.
Device automation is pretty good too..
There are OSS apps on F-Droid and some are quite good.
Having OEM unlock Lineage OS support means after OEM discontionues support you can unlock bootloader and install LineageOS.
Or if you are feeling adventurous, I suggest to check about pinephone which runs linux, although I don't know much about pinephone - just heard about it once on linux subreddit.
Or, Apple sells the XR at $499, which I think for some folks could be a better deal. It gets you a more modern form factor, should have a better camera, and will definitely have better battery life than the SE under heavy load. Also, in my opinion, the gesture-based system found on iPhone X-style iPhones is greatly superior to home button equipped iPhones.
The XR (or the 11) is on the larger side, though. The best thing that Apple sells that’s as small as possible is the iPhone 11 Pro. You could pick up an Xs or X instead to save money - but the 11 Pro has much better battery life than those. Still, all options will get you to the end of the day with light usage.
Don’t forget to buy any storage upgrade you need up front. Don’t forget to check Apple’s own refurbished store, which sells devices that are essentially new with the same warranty at a discount.
I don’t even think Android is a decent consideration for what you want unless you specifically shop for something that works well with custom ROMs. Android software support is just too short. And it really sounds like you want a phone that doesn’t eat up your time with tinkering and tweaking, Apple fits that bill. And you want to take pictures - with Apple you basically just can’t go wrong with the cameras. They’re always simple and fast, with unopinionated results.
For small-ish phones, probably the only decent Android choices are the Sony Xperia Compact line or the smallest Google Pixel phones. Almost everything Android is huge. I believe this is due to their poor battery optimization where every device needs a 4,000 Mah battery just to get through the day.
The Pixel 3A could work for you but it isn’t sold with more than 64GB of storage and it’s a lot slower than the new iPhone SE.
Apple will get you at least 5 years of software updates (which is on an increasing trend) with their phones since their release date. They have a high resale value and migrating from one to another is a breeze. Even when you lose software updates, the App Store and most apps continue to work for a long time. Apple even recently patched FaceTime so that it wouldn’t break iOS 9 compatibility (which is 4 versions ago). In contrast, the original Pixel just lost software updates, while its Apple contemporaries remain supported.
While the idea of owning a long-lasting phone like a ThinkPad is appealing, I don’t really think it ends up making a lot of practical sense just given the fact that phones aren’t really sold that way. I think that, on an economic level, the best way to have a reliable supported phone at all times might be to simply buy Apple’s 2 year old phone every year, and then sell it the next year in favor whatever the next 2 year old phone is. If you do it that way you essentially avoid the frontal depreciation and you’re probably spending $100 a year or less on a phone after you sell the old one, and never losing software support or running with a busted up phone.