In 2003 I designed a simple web site for my brother, Dr John Worthington, who is an Educational Psychologist. This consisted of about a half dozen pages of text with a photo and some links. This has proved adequate, with medical practitioners using it to refer patients to the services. Many people print out the relevant page and bring it along for a consultation.
He asked for a small change to the home page and I did a quick check of the code. I found one minor error to fix. Out of curiosity, I ran it through the W3C mobileOK Checker, which scored the page at 80/100. Even so there were a few problems found, which I will fix, but leave the page otherwise unchanged.