I personally gave up on an old Lightroom version that was pre-CS cloud, and could see more professional people clinging to specific version of apps for whatever

I personally gave up on an old Lightroom version that was pre-CS cloud, and could see more professional people clinging to specific version of apps for whatever reason (private plugins, specific Apple scripts, standardized manual procedures etc.). There must also be enterprise software that still weren’t recompiled or the vendor went under or threw the towel. Those are a minority, but sadly we see that on every breaking change.