I see no use for the numlock key, I'd rather just have the numpad on the whole time. Are there actually cases where it is useful or people who for some reason prefer their numpad turned off?
Yes. On my keyboard there's no separate "end" key, it's part of 3 on the numpad, that key is very useful when using the terminal, because you don't need to wait for 5 years for the cursor to make it to the end of your command.
If you have keyboard software, you might be able to use that. I use autohotkey for reassigning keys. The script would be:
SetNumLockState, AlwaysOn
NumLock::End
For windows,
Just put it in a txt file after installing AHK and use .ahk at the end of the file name. There's a way to make it the default script, but I think but I use just task scheduler to make it start on boot/login.