I can't think of a single game that manages to have enemies correspond to your level rather than area or story progression actually contribute to the game. It just makes trying to get better gear ultimately a pointless task because the enemies get strong at the same rate so you might as well stay weak.
I think the line is an implementation, not a concept. Like, if the code from the lord of the rings game was put directly into another game that's obviously a problem, but if you work from the concept it should be different. like how if I build the same engine as someone else that would be a problem, but building an engine isn't.