Another potential big issue is the community itself. A huge reason why LinkedIn is so hated is the community that's on there, and how the various engineering/design choices made by LinkedIn over the years amplifies and encourages those behaviors. Things like humble bragging, writing styles, DMing patters, etc etc etc.

And I don't know if building another platform with a feed will solve that problem. Because the existence of a social feed itself might be the issue here. But then what do you have if you don't have a feed? Is that a "platform" anymore if all that's on there are peoples' resumes?

I feel that building the next LinkedIn is really building the next LinkedIn community. That can't necessarily be done through computer code. I mean, look at the kind of community building that it took to build out HN.