I had a lot of similar feedback in my feedback post (Diablo 4 Beta Feedback)
Particularly the ‘shared world’ - it really really doesn’t work. It is definitely the biggest ‘con’ in terms of Diablo 4 over other ARPGs. Running into other people randomly is just not a positive diablo experience in any way shape or form.
Even if they are ‘nice’ and save you from enemies that might’ve otherwise killed you… that’s still not a positive. I want that feeling of threat to sometimes be present.