Earlier quoted context omitted.
iPhones have longevity. The iPhone 5s from September 2013 has been receiving regular security updates, the latest being iOS 12.4.8 on Wednesday. It was the first 64-bit phone, and first iPhone (first phone?) with a Secure Enclave. They can be had for <$100 in good condition.
BTW, every one says this - but nobody uses it like a daily driver. Yes, it will work as a spare - with just one app - like whatsapp - but for many poor - they need 1. Uber or Ola 2. Facebook or WhatsApp 3. linkedin to whatever local app 4. youtube Why dont you try to use it for a week with all your existing apps? If it works as good - why would anyone buy newer?
You should try using it before telling people it doesn’t work.