There is an interesting comparison to be made between most of the crap we use today that isn't serviceable and is proprietary. My favourite devices growing up were Gameboys, and an iPod nano which wasn't serviceable realistically. I have all of my Gameboys up to SP in a box, I can pop standardized batteries into them and play them with at least as good performance as 20 years ago. The Nano malfunctioned after about 4 or 5 years and despite it being the first thing I spent more than $100 of my own money on, stopped being useful. By contrast, here's the ifixit guide for replacing the lithium ion battery in a DS Lite.

https://www.ifixit.com/Guide/Nintendo+DS+Lite+Battery+Replac...

and here's the battery that you can order for $15 on Nintendo's official store. https://store.nintendo.com/battery-pack-nintendo-ds-lite.htm...