I spend quite a bit of time doing that too. I just really enjoy popping into someone’s game and helping them through a level or a boss encounter. When you join and there’s the host standing by a shrine right before a boss encounter that starts cheering when you show up, you get the impression they’ve been getting their butt whooped for a while.
I’ve gone through most of NG (is that the correct term for the first playthrough?) in Expedition mode with a friend. Dark Souls desperately needed this sort of thing. Dark Souls was fine for a quick coop experience but trying to play through with a friend (or worse, two friends) was an absolute nightmare of trying to see each other’s signs and having to play through each map/boss three times.
I’ve found Expedition mode to be more challenging with the two of us than playing solo for the most part, although there are obviously advantages. That’s also been something I’m really impressed with: usually coop in these games makes them significantly easier and that’s definitely the case for summoning visitors. But Expedition mode, they did a great job increasing the difficulty in a way that makes things challenging without becoming “bullshit” by massively increasing HP or damage of monsters. They achieved a really good balance of buffing enemies and adding additional enemies to the maps to keep it challenging but fair.