bi pedal humanoid robot is probably the worst type of robot there is out there if you've ask me.

Why walk when you can put wheels on yourself? Why build a head when you can contain everything within a 'torso' unit and protect with tons and tons of armor?

Reason for them to exist is technologist want to make them more 'human'. Logical perspective into consideration like cost, efficiency etc. Humanoid robot IMO is best used as, guess what? A non-organic pet

Artificial Intelligence is well, artificial. It's all scripted and the robot simply follows a logic path. A scenario in I-Robot where the main character(Will Smith) fell into the water with another small kid. The robot rescued him instead of the kid because analysis worked out that he has a better chance of survival and in that kind of scenario, all AI with the same code/script/design will do the same thing. Human intelligences permit other outcome to such scenario even if we're given the odds of survival.

Self learning robot is still far from reality. Scientist claim they're able to make robot learn by themselves. I take another scenario. A self-learning robot picks up a cube, using sensor and determined it as a cube, what if I remove the programming that was placed inside of it's processor before activation to recognize cube? Well, the bot can take out the encycloped... oh wait, do they even know what a book is?

What's behind the scene that drives human intelligence is something eluded scientist. I don't believe we're anywhere near in developing it, let alone perfecting it. Robots and AI still need the creator, us(humans) to give them the power of thought. The infamous fictional Skynet can be a reality one day, it's dangerous to have too much intelligence(even artificial one) minus the proper amount of humanity backing it up.