Spectator-mode to make game MUCH more social...

I think this game REALLY would benefit from a spectator-option so that anyone can have their friends (or others) to spectate what you're doing - it would be a perfect way to "hang out" with friends in the game, as well as give beginners tips to their play (if you watch them) or show them how you do things (if they watch you).

EDIT:
Example. I come online, a friend of mine is on discord and is like 10 minutes into the Marion quest - I'm about to eat and chat with him during... it then would be awesome if I could just "tune in" and spectate his active game while eating and talking with him on discord.

I saw someone suggested this for coop-play specifically, but I think it would be best if it's possible to "dive in" and spectate even if someone just started a game and you want to jump in and watch.