Yeah steel used to be big in Europe and Lenin even talks about it at length in Imperialism. Then it led to a crisis of overproduction and eventually wasn't so big anymore lol
The problem HOI4 runs into is like you said, the rest of the world doesn't have that many interesting resources. You can eventually produce everything domestically with tech. At most Southeast Asia has a lot of rubber.
Tbh these games would make more sense psychologically if we abstracted them completely and put them in like a brand new original fantasy setting. You see Germany and you think it has to be historically accurate, but it's a game first and a simulation second. Some things have to be balanced for gameplay -- the AI needs those resources because it's systematically a worse player than any human with sufficient hours in the game. They also don't want an African tag to start conquering the world, they want to give you a WW2 simulation contained inside a game.