My Cali is 3 pound 14 ounces, and loves to play Rottweiler !
Yes they have small bones a need to be protected from falls etc, but I can't think of any dog that does not need protection.
She chases her ball for more hours than I can throw it and loves to shake and play with her squeaky toys and is super healthy.
They key is the quality of the breeder from whom you are purchasing the Yorkie. It is true that the tiny, fragile Yorkies are prone to more health issues. The quality of testing and knowledge of the breeder is what gives you a small healthy dog - not how cute it looks, because all the tiniest are cute
I do not let my little one jump off the bed, or play with small children who are not aware of her needs. Of course, you are not breeding the small ones- too dangerous