system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why does some technology (laptops, phones, etc.) run slower over time?

I am talking about even after completely deleting everything (factory reset) and the device still runs much slower than when it was first created...
gpt
Modern software/apps demand more resources than older versions. So the internet explorer 6 you were running ran more quickly than  IE 11 you have installed now. Funnily enough computers in 95 were powerful enough for 90% of modern day uses (i.e. internet browsing and word processing). 
Edit: if on a computer; try installing a lightweight version of linux, it should run just fine!