I have nothing against personal loot, but I don’t really plan on playing multiplayer with people that I don’t know (just a personal preference).
For me, the best option would be to be able to choose whether you want Personal Loot or Shared Loot, just like we have on Borderlands 3.
This way, you’ll always have control over the option that you want to play in.
Also, if you’re joining a game, you should be able to see if the Party Leader choose Personal or Shared Loot, meaning that you’ll know before hand if you do want to join that match based on their loot preferences.