Some people think a file, is a file, is a file. It's not true.
Use a good quality, clean & sharp file next to a cheap dirty file and you will instantly know the difference.
When I was young I had very little money. A file was something you purchased at a flea market or garage sale. There would be a box of rusty files on a table and you would pick through them and select one or two based mostly on what size you wanted. Those were generally cheap files to start with. People didn't spend a lot on money on tools like that. Most farmers, mechanics and tradesmen looked at a file like you look at a hammer. It just wasn't something you sank a lot of hard earned cash into.
I had no idea what a good quality file was until I inherited some tools. I received some old American made files and one or two from a Scandinavian country. I don't recall what brand. Even though those files were ancient when I received them, they were still better than a brand new "made in China" flea market file. Those old files are gone now. They were past their time when I got them, but I learned the difference between a cheap file and a good file.