It really depends on your business. How old and established is your brand? Who is your target audience? And what level of functionality is appropriate for your business needs?
Brand new businesses on a shoestring budget may be best to use a template website because there's no budget. But generally, once the business can afford to engage an experienced and talented web professional, they should do so to maximise their growth potential.
A talented web professional or agency will bring value to your business in ways a template website cannot (and in fact a template website will commonly devalue your business, see related article).
A custom designed and developed website created by an experienced web specialist will help grow the value of your business in increasing degrees. This will result in a superior website experience, one that is unique, tailored for your brand and aesthetically beautiful. Furthermore, the functionality delivered should be completely tailored to your business needs and completed by a professional with proven back-end experience to create a site that simply works and is easy to use, creating cost saving efficiencies for the business.