There was a time when game didn't have DLC back then. Right now almost every game has it.

Back then, we didn't had DLCs or "patches". When a game was released, it was expected to be of top-quality as it is. If it had any errors or mistakes, that's the developers fault. Now days games often have "patches" which excuses developers from bugs and errors.
And while we didn't had DLCs back then, we had expansions.



(And every "third version" Pokémon game since.)

DLCs are pretty much the same content, just shorter and cheaper.