>>280910326
>The ending, as I understood it, seems strangly nihilistic and sort of seems to say "Let's just all kill ourselves because then we can't harm each other anymore,"
the very next scene is Lain going mad from loneliness with nobody to talk to but herself, and then the final scene is her choosing to start interacting with Humanity again and seeing Arisu in person.

The explicit message of the show which gets repeated verbatim is "No matter what, we're all connected," meaning no matter what you do you can't truly escape your connection with the rest of humanity. Eiri saught to transcend humanity to become a true YaHhWeHh-esque God. Lain sought to spare humanity from anyone taking advantage of her ever again by basically becoming a hermit. Most of the characters in the show are ultimately using The Wired to run away from the people in meatspace that affect them or to run away from their own human flaws and the people that remind them of those flaws. and every one of them fails because that connection can't be broken no matter how thinly you stretch it. In a very literal sense in Lain because everyone is hooked up to the Noosphere but also more broadly in that even in the total absence of other humans in your life, your awareness of the absence of other humans remains as an emotional connection to Others