The companion system is definitely a weak point. The companions themselves are fine, but you can’t refuse any and have very limited choice in party composition.

You can disagree with them at some points, and you can influence their story, but the gameplay impact is pretty much nothing.

The impact your choices can have on the world are definitely bigger - and visible in the game itself. I won’t spoil it, but there’s a pretty huge consequence not long after meeting Giatta.