The ability to copy text or images from a PDF depends entirely on how the PDF was created and whether the creator has applied any restrictions to it.
PDF files can have different levels of security restrictions. For example, the creator may allow you to view the document while preventing you from copying text, extracting images, editing the content, or printing the document. These restrictions can be configured by the creator using software such as Adobe Acrobat Pro.
In some cases, you may be able to open and read a PDF without any difficulty, but you may find that the options to copy, select, or print its contents are disabled. This is not necessarily a limitation of the device or operating system; it may simply be a restriction imposed on the PDF itself.
These restrictions are embedded in the PDF file and cannot be overridden through the normal settings of an iPhone, iPad, Mac, or any other device. Changing devices or switching to a different PDF viewer does not automatically remove them.
Therefore, if you are unable to copy text or images from a particular PDF, the first step is to determine whether the document has security restrictions or whether it consists of scanned pages rather than selectable text. The solution depends on how the PDF was created and the permissions granted by its creator.