Adobe Reader

Install Adobe Acrobat Reader DC on Mac OS - Adobe Support

- You need Mac OS X 10.9 or later to run Acrobat Reader DC. If your operating system is older, you can install an earlier version of Reader.

Adobe Acrobat Reader DC Download | Free PDF viewer for ...

From the source you are fine—Depending on your Preference settings you may have to Control click to open the contextual menu to open or open the application.

Safely open apps on your Mac - Apple Support

Sally,

If you are downloading the current Adobe Acrobat Reader DC from the Adobe site, you should not receive that browser warning, though FireFox 74 may think it is protecting you. Safari 13.0.5 should especially not warn you, unless you have inadvertently installed ad/malware, or attempting to obtain Acrobat Reader from a download aggregation site instead of Adobe.

Although Apple's Preview is ok for ordinary PDF, it cannot fully cope with PDF standards such as PDF/A, PDF/X, ill-formed PDF, and certain PDF created by InDesign that embeds requests to use Acrobat plug-ins. Adobe is in the position to keep the PDF standards support current in Reader, while Apple cannot do so with Preview. This can make the difference in what is imaged in the viewer, and how JavaScript behaves behind PDF form fields.

Is there a reason Apple's built-in Preview app isn't suitable? I find Preview works well and doesn't require constant updates from Adobe.

HWTech wrote:

Is there a reason Apple's built-in Preview app isn't suitable? I find Preview works well and doesn't require constant updates from Adobe.

It does not support all the functionality of PDF.

+1.