Latest versions PS, LR and BR not compatible with my Mid 2012 Apple Mac Pro

@erikw1956,

I'm still using a previous PS version because my graphics card is not good enough to support newer PS.  It's no problem for me.  It should be no problem for you.  

PS doesn't need security upgrades per se.  But your operating system and browsers do to protect you from Internet threats.  But that's a different matter. 

Also if you buy a new camera, you might need new software to support it.  But again, a different matter.  Older versions of Photoshop will continue to run just fine if you don't make any changes.

When you're ready to get  new equipment, make certain it meets the new system requirements to run CC + OS + all other apps you plan to use.

- https://helpx.adobe.com/creative-cloud/system-requirements.html

Pay particular attention to Photoshop's new GPU requirements. See links below.
- https://helpx.adobe.com/photoshop/system-requirements.html
- https://helpx.adobe.com/photoshop/kb/photoshop-cc-gpu-card-faq.html

you don't need to update your adobe programs.  you might want to update them if there's a new feature that you can't live without.

that can be contrasted with your os which not only lacks features of newer os'es, but more importantly has security issues.  

bottomline: if you can live with an old os, you should be able to live with old software.