laready did many times in past, and people were mostly joining to level up or do quest. “hijackers” are not that common so unlike you i have actualy experience.
Omg , it was already explained here that reason for that is because lobby is broken. You dont see games which are open outside of your small radius. Its not because people dont want to join or play together. Its because they dont see the freaking games others made.
When I was playing PTR season I didnt see one game on HARDCORE whole time, then they deployed fix and suddendly I saw like 20 games on hardcore.
Its not dead, people just dont see the games others made outside of their range.