Choosing between BuddyPress and non-BuddyPress Community

My only prior background with WordPress is for single-user blogging.

I'm now building a community site, and I'm unsure whether including BuddyPress is a good idea or not. It seems like all the functionality is available with separate plugins, and I'm not sure why. Is it just so that you can pick and choose a la carte, if you don't want the full suite of BuddyPress features, or is there some other reason?

I know I want chat, forums, friends, and private messaging. What should I keep in mind when deciding whether to use BuddyPress or a la carte?

Any insight would be greatly appreciated.