What's the point of file permissions if cp -f overwrites the file anyway?

Question

linux

What's the point of having permissions if without sudo basically anyone can overwrite a file?

Answer 1

Because this is the same user's file, with cp -f it first deletes and then copies.

Answer 2

Answer from Timeweb support.
The -f switch deletes the file and recreates it if the destination file exists and cannot be opened. More details in man: https://pingvinus.ru/note/cmd-cp