It is the middle of a busy week in Oakland County, and a client texts you a screenshot. Your site shows a browser warning, or worse, a page selling something you have never heard of. The person who set it up moved away years ago, and nobody has touched the plugins since.
With care and hosting in place, someone watches the site every day. Updates go in on a schedule, backups run every night, the security certificate renews on its own, and if something breaks we fix it before you hear about it.
The site becomes the one thing you do not think about. Hours change, a new service goes up, a photo gets swapped, and you just send a text and it is done.