Actually it can't because Bitcoin is a naked blockchain and you will be able to look at it in its whole glory. What mixers do is essentially allow you to occasionally hide your face. Sure, someone who doesn't know about your mole on your left thigh might not recognise you, but the rest of you is still exposed. Even worse, because of the high fees involved in moving funds around, you're paying a high fee for that face mask.
All that makes Monero private was originally developed for BTC, they didn't implement it because it is controlled by bankers and they do not want competition for their scam fiat "money".