Soloing the story is advisable, lest you miss out on parts by match-making and loading screens cutting off story bits and cutscenes. Or outright dropping you into final mission spoiling it all in one go. Or just players rushing through and getting it done with without much moment to take it in.
The last sentence is PRECISELY why I find it hard to play these games. I love to savour a well written story and take in as much detail as possible. Found it annoying in The Division when I'd party up and then have to endure someone racing like mad through levels and ruining the pace and timing of the story. Yes you can play it singley but it's designed for co-op and I think you lose something there when playing on own.