Welcome to YT!
It's not always bad-it just depends on how much and what type you feed. Chicken is good for most dogs-but NEVER give a dog cooked bones of any kind. It needs to be unseasoned and no fat added. Cheese is ok in moderation-lowfat is even better.
The reason these things can be bothersome is if your dog is liver or pancreas compromised, or has other health issues where fat and protein need to be monitored carefully.
Some yorkie owners feed kibble, others raw or freeze dried raw, other prey model, and other home prepare dog foods. It just depends on what works best for you and for your dog-as well as your lifestyle and budget.