A) Establish the expectation that websites "close" in the middle of the night for ~5-6 hours, local time / for each timezone. I don't know if would best be done via cultural influence -- giving talks, writing essays, personal communication, testifying / making inroads with politicians -- or via creating some sort of protocol. The idea is to prevent the unhealthier aspects of internet binging and screen addiction.
B) Establish the expectation that internet comments are transcriptions of voice recordings. I.e. to leave a comment, you have to call a phone number and leave a message which then gets transcribed as "the comment." In order to respond or reply to a post or a thread, you have to listen to the message and tone of voice of the person you are replying to. I don't think this would solve every internet dialogue, but it'd promote healthier interactions and less division.
In my book, the largest problems with the internet are techno-cultural, not technological.