I really like the idea of a party made up of friends you meet along the way. In Pillars of Eternity 1 in particular, a good chunk of companions are travelling with you because you're helping them and that eventually just turns into them sticking with you because they want to help and support you. Meanwhile one of the things that really stood out to me about DA2 in subsequent playthroughs is the fact that your party is literally justa group of friends. In both games, you're not really tied together by plot aside from a few instances, and I think that gives a good degree of freedom to the story and cultivates a unique atmosphere.
I don’t recall the details of PoE but I agree it works really well in DA2. For me, I think that’s because you’re based in one place and the companions all have lives outside your adventuring (which I *love*) and you’re not asking them to drop everything and relocate their lives to do whatever you want or need but usually just to pop out on a short jaunt. BG2 also has elements of this of course, and there are some companions (eg Keldorn and Cernd) who I most often help sort their lives out then leave them to it, and I didn’t mean to imply it doesn’t do a reasonable job of giving a rationale for joining. Just that it would be possible in my view to do better!
Regarding friendship as a motivation for working together more generally, for me really feeling like party members are friends tends to take a while, so it works best when there’s a strong motivation to stay together for an extended period while the relationship develops. And even after that, I’d probably still prefer the feel of a party working together for a (largely) common goal that they have their own reasons for pursuing, than folks who are just coming along to help my character. It just somehow makes the party feel more real to me, and I actually love moments of feeling that my character is just one member of a group working together - or against each other - for their own reasons rather than the hero.
I don’t think there are any hard and fast rules here, though, and it’s mainly a matter of degree given most cRPGs at least try to give each party some motivation for tagging along beyond “I like you, why not?”. Plus different approaches can work in different games and for different gamers!
