Thread:CheeseBurgerGuy/@comment-28092650-20191106005103/@comment-35606925-20191120030429

I think the reason for it is very simple actually.

In the first game, Professor Oak served as a father figure for the main character. It's also the fact that gen 1 was much more a coming of age story.

The same applies to Lance, Oak, and Elm in generation 2. It was also for the sake of only having one NPC to save your money with instead of having a second pointless one.

For generation 3, the main characters did have fathers.

After that, it was kind of a cemented tradition.