Firstly, I don’t believe all businesses should have a website. Or rather, not all have an overwhelming need for one.
Many local businesses have no plans for massive expansion and derive most of their custom from walk-in customers who saw their store, and from word of mouth. They likely wouldn’t know what to do with a website if they had one.
However even for those businesses I believe there is a use for a simple website – generation Z (and beyond). Many of the younger generation look to the net as a first port of call when searching for a business to solve a need. If the only reference they can find to a business is an online yellow pages listing (probably missing most information), they will tend to give that business a miss.
It need not be a flashy website that allows customers to buy things -it can be nothing more than an online “brochure”. Likewise it doesn’t need to cost the earth. Like many other realistic web developers, I charge a modest fee to develop a website, and any ongoing costs are only related to your choice of how/where you host your website. I develop sites using Drupal and WordPress (even one page brochure sites) as it allows any other Drupal/WordPress developer to add to your site at a later date, and a one page site can be scaled to a large ecommerce site later if the need arises.