[Spoiler] Humans on earth

[Kein]

I do recall a lot of pictures or computer terminals that implied there were many more underwater facilities in the Pathos global network

Can you post the screenshots then? Because I do not recall a single one. Gameonly mentions PATHOS-II, there was nothing about PATHOS-I. Additionally, the numerous characters in the game (audio logs + Catherine) keep repeating "they are indeed the last humans on earth".