Nice vid! I love the PS1 so it's always nice to find out more about it. So, now I know that both the PS1 and the N64 had limited internet access with an add-on. The late 90's must have been an interesting time to be a gamer in Japan!
I used a time stamp to skip right to the section that covered what I'm talking about here. But did you see the bit before that about the Namco arcade cabinet that allowed PS1 & Dreamcast to arcade cross saving? Here's a photo of that cabinet that had ports for S1 and Dreamcast memory cards: