Contrary to what you might think, games received updates far earlier than the introduction of DLC and Micro-transactions. Doom, for example, had many update patches post launch. Only, the game wouldn’t update automatically. You had to know that the patches existed, and where to find them to download them.

Games are actually different in so many ways other than this, that I can’t make a straight comparison, other than to say that before DLC, you just bought expansions on a disc, and before that, you had to buy an entirely new “Turbo” or “Super” edition of the game to get any updates.