Obviously I understand that iPhones and tech generally are designed with planned obsolescence and are certainly not "BIFL" products. However, we have to live with them, and as far as I understand, there is no BIFL option when it comes to smartphones.

I have been using my iPhone SE (1st gen) for almost 5 years now, squeezing as much use out of it as I possibly could. It is truly at its last leg at this point - I have to have it plugged in all day, it can barely run most apps, and multi-tasking is literally impossible.

Unfortunately it is unusable at this point and the time has come for me to upgrade. Which iPhone should I buy, now in late 2021? If I have to make a $400+ investment, I want to be sure I can get at least 4 good years out of it. I am a digital minimalist; no social media, no heavy usage of advanced apps, nor a need for a super-advanced camera. Really all I want is something with a very good battery and is a good bang for my buck. I was disappointed to read that the new iPhone SE has poor battery life, so I am wondering if it would be worth it to buy an X, 11, or 12. I also can't make sense of all the different versions out there and what all these R, S, Max, Pro, Mini qualifiers mean.

I appreciate any tips y'all can provide! Thank you