If there’s only one person who can do the website, and rather than having him or her teach other folks the ropes, you ride that person hard till they break (vote with their feet), then your website is dead.
That was silly, wasn’t it? But how many groups analyse who has what skills and what the single points of failure are?
It can be done, easily, but usually isn’t…
Wikipedia: A single point of failure (SPOF) is a part of a system that, if it fails, will stop the entire system from working. SPOFs are undesirable in any system with a goal of high availability or reliability, be it a business practice, software application, or other industrial system.