I agree with no JS, but why PDF over HTML? Hard-wrapping for letter-sized paper (ok, a PDF doesn't need to be letter-sized, but most menus are approximately that) with crapshoot reflow options for soft-wrapping in certain viewer apps is pretty dicey on a phone, mitigated only slightly by rotating the phone sideways.

The only benefit I can think of is if it leads to more frequent updates by the restaurant, due to limited skillset.

The complexity between the modern web and a pdf is marginal. PDFs do get printed for menus. Editing a PDF and uploading it to the site, integrating prices and syncing between the site, online ordering, PDF menus is just part of the business. There are lots of platforms that help with this such as Slice.