system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why do games have “press any button to continue” before they start?

I mean specifically before the main menu of a game even loads. Such as fifa, rocket league, battlefield, etc...
gpt
Its an old leftover requirement.

Basically it sets which controller or input method the game will pay attention to. So for example if your system has 2 controllers whatever one you press becomes player one.

It is still a requirement for games to pass certification and ship on consoles, thus you see it everywhere.