Agreed. Birds have an inheren limit on head weight, which limits their brain size. They do manage to use what they have quite well (parrots are also remarkable in that regard), but the limit is there. Ultimately intelligence is a tough nut to crack for such a stupid and limited thing as evolution: some have a big brain but no hands, some have hands but cannot have a big brain because space is used for something else (e.g. bears), some have hands and space for brains but cannot increase head weight because not erect walking etc. Once you're erect, there's a tendency for arms to atrophy (think T-rex and ostriches). Jaws and the nasal cavity tend to take up space too, so an intelligent species needs to have weak olfactory sense and be a meat/fruit feeder. It's a miracle that a species like ours could combine all the necessary, quite fragile, ingredients to develop intelligence.
Nope, the anthropic principle does not imply that probability is 1. It's not even really a principle, just a post-factum observation. There may have been no one on Earth to write this stuff on a smartphone, ever. There might have even been no life in our Universe, ever. We shouldn't take these things for granted.
