The answer to this question is somewhat complicated. Different factors can affect how long a vehicle lasts, including how often it is driven and how well it is maintained. While towing may put additional wear and tear on a vehicle, it is not necessarily true that it will shorten its overall lifespan. Some vehicles are designed and built specifically for towing and can withstand the rigours of regular towing without any significant decrease in lifespan.
Other vehicles, particularly those that are not designed for towing, may experience more wear and tear when used for this purpose and may not last as long as a result.