I agree with the others
It isn't often very straightforward in my experience, no. Most (not all, but most) adopted children and young adults I know, do have additional needs to a greater or a lesser degree because of their early lives/background. Sometimes they don't impact on family life much, sometimes they do.
But that doesn't mean you can't be happy as a family, even if things aren't straightforward. I certainly can't think of any families I know that never have any happy days whatsoever. I DO know families who are happy with their children who have additional needs and challenges.
I've had incredibly challenging times, but I don't regret adopting my wonderful children. I also know that my adoptions have been successful. Success doesn't mean everything being easy, and success doesn't mean I've never struggled, because God knows I have. It means that my older children have reached adulthood in a safe and loving home with a mum of their own, the biggest chance they could have had to reach their potential. It mens that they consider me their mum, and it means that I remain committed to them forever. That's success. I appreciate that other people define success in different ways, what with it being a rather subjective word! But for me, it just means a legally completed adoption, committed parents and a belief that you are a family for good (whatever your circumstances)
To be honest, I think internet forums just aren't many people's 'thing' whatever their situation! I do tend to start threads of my own when things aren't so easy, and don't start threads saying 'everythings going fine'. On the other hand, when things are at their worst, often I just drop off and stop using the forum for a few days because it's too much. Personally I think this forum has a pretty broad spectrum of situations, from those whose kids have few needs to those of us whose kids have more significant ones. In fact, we have few parents in the most difficult situations, they tend to congregate on one specific forum which isn't this one.
PS. I think having a friend who cares about you enough to research adoption and read adopters forums is great! Support from friends who have some understanding of how modern adoption works can make the approval/matching process much easier, and a listening ear really help later on in parenting as well 