The first thing you should consider doing with you old device is selling or giving them away. This helps lowering the need for manufacturing more hardware, it prevents the hardware becoming e-waste in a drawer, and it put pressure on the market to lower it's prices.
Sure, you can reuse as a NAS, but someone probably needs it more.
I attempted to replace my 13 mini's battery today using the iFixit kit. I broke the OLED panel doing so. Removing the screen take much more force than I though.
I did this hopping to keep my iPhone maybe 2 more years. Now I am waiting for ordering the 17 next Friday. I will have to manage having half of my screen being white until then...
I'm very happy, I will buy it if it has the same spirit has the previous ones. I loved my Pebble Time, I am not sure why I sold it. It was just what a smart watch was supposed to be, not a mini smart phone on your wrist.
Buttons instead of touch screen.
Long battery life.
Always on display.
Simple to use.