When you care for someone's animals you have taken on a serious responsibility. Granted, with most critters (even my muttley crew) it isn't terribly taxing work most of the time - but that's not what I really pay for. I pay my sitter to be 100% responsible. I pay my sitter well, knowing that she takes the welfare of my mutts to heart, knowing that she will keep them - and all with whom they come into contact - safe. I pay for peace of mind.
(In fact, a third party paid to care for an animal can be held legally responsible should an accident happen while the animals are in his/her care. Hence the suggestion of liability insurance.)
FYI, one reason for the new education/registration requirement for dog carers is fall-out from the Oberglatt tragedy. At the time of the incident, the dogs were in the care of someone other than the owner. While I think the education requirements in the TschV are way overkill, the goal is understandable. The law seeks to improve dog owner's skills and knowledge and responsibility - that it also seeks to do so for dog carers makes sense.
When choosing a sitter, you should ask yourself:
What if your pet is injured or becomes ill - is your carer capable of performing first aid and then getting appropriate emergency veterinary care? He/she should be.
What if the unthinkable happens, your dog causes damages or injures someone - is your carer capable of taking the necessary steps to resolve the situation? He/she should be.
Better yet, are you certain that your sitter will as a matter of course take all necessary precautions to prevent the above from happening? You should be - and you should have thoroughly tested the sitter's skills and decision making before leaving your pets in his/her hands.
My advice to pet owners and carers - make sure all responsibilities and expectations, all the 'what ifs', are spelled out in writing.
As said, it's not necessarily the work, but rather the responsibility , that one is paying for.