It is generally a good idea to mark up all relevant entities on a page using JSON-LD, as this helps to provide more context and meaning to the content, However markup is not an all-or-nothing choice. marking up as much content as possible helps search engines use your information to present your page to users in the most useful way. As a general rule, you should mark up only the content that is visible to people who visit the web page and not content in hidden div's or other hidden page elements.