I do not want to hear things which are about computers - 8 bit byte, sim cards, keyboards etc. Just some random examples of regular things - weapons, kitchen environment, wear, sports equipment, maybe cars - anything that has not changed since at least several decades.

For example, I am fond of banana boxes [1]. They are extremely popular among banana sellers, they are always the same and I can freely use halves from different suppliers. Their killer feature is that this is the strongest cardboard box I know. I have ordered a custom barbeque which has been made exactly to fit in a banana box because I know what it is to transport one banana box and also I know that I will never lack those ones. One dollar buys somewhere between 4-8 used banana box per dollar depends on wear. I hope that plastic banana box will never replace good old paper ones because sellers use to repair them sometimes (typically handles) and I can't believe plastic ones can be repaired.

[1] https://en.wikipedia.org/wiki/Banana_box