FWIW, I only bought a smart phone in January 2019, and only then because my ~10 year old Nokia gave up the ghost (pity, as it had more than ten times the battery life of my iPhone). My wife had the same Nokia as me, and whilst hers hadn't suffered from the ravages of being on a building site for a couple of years, it was, like mine, on it's second replacement battery, and so was probably going to die before too long.
We both bought iPhone SEs, only because they were not much bigger than our old Nokias and were on special offer, so were the cheapest "brand name" phones we could find at the time. Bit of a waste of money, really, as I've only made about half a dozen calls on the thing since I bought it, and only really have a mobile for emergency use when out and about, most of the time it stays turned off. My phones have always lived in the glovebox of every car I've owned over the past 20 years or so, something I had to stop doing when I bought the Model 3.
I couldn't really care less what make of phone I have, TBH, as long as it's small and works. If it was easy to buy a small phone with proper keys then I'd get one, as, try as I might, I just can't get on with typing stuff on a touch screen. I have an Android tablet (an old Sony Xperia) and trying to type on a screen, with no haptic feedback, caused me to get an add-on Bluetooth keyboard for it.
It might sound a bit Luddite, but the most important attributes for any mobile phone for me (and I've owned one since 1990) are long battery life (ideally something like the two weeks plus that was normal before smart phones came along), an easy to use interface (keys and a clear and easy to read screen) and small size. The form factor of the iPhone SE is OK, but it's too wide, ideally something narrower, even if thicker, with a robust case, that easily fits in a shirt pocket, would suit me.
It's not a lot of fun trying to read a phone screen at arms length, just because your reading glasses aren't easily to hand, and it's even harder trying to use a touch screen when you can't see exactly where your fingers are on it (due to the aforementioned absence of reading glasses issue). At least with real keys you don't need to see where your fingers are, you can just pretty much do everything by feedback from your fingertips, plus memory of where each key is.
This might sound daft, but one thing that worries me slightly at times is just how long it might take me to phone 999. Because the battery runs flat so quickly on the iPhone (i.e. a day, rather than a couple of weeks) it's usually turned off. Because I would need to find my reading glasses to see the screen, I won't be able to just key in 999 by feel. All told, that delay might possibly be critical, one day, and is one of the reasons I've been waiting to see if the Blackberry re-emerges from the ashes. We had Blackberries as work phones, mainly because they could be made pretty secure, and they seemed to be a pretty good compromise, having a long'ish battery life, reasonable screen and fairly usable keyboard.