Companies want you to buy their newer games and rereleases of old games, not go to a website and just download it. Usually theirs no differences to the games besides graphics unless you’re f**king Nintendo and pull “this has 2-3 games in one cartridge/adds some mini games to your game” or “lets add mega Pokémon to this game/make certain fights a lot more difficult and change/add some content.” Most of the time, companies will just port the game to a new system with updated graphics (Nintendo does this too).