The biggest issue is that CS6 is stuck in 2012.

While CS6 is an incredible tool, it does lack modern features like Lumetri Color panels, essential graphics, and native support for 8K HEVC files. However, for 1080p or basic 4K editing, it is often faster on mid-range laptops than the resource-heavy Creative Cloud versions.

My lengthy Adobe Premiere Pro CS6 review now online by Scott Simmons

Adobe Premiere Pro CS6 (released 2012) is a professional non-linear video editing application from Adobe's Creative Suite line. It offers native support for multiple video formats, a redesigned user interface with Mercury Playback Engine for GPU-accelerated playback and rendering, expanded trimming tools, improved media management, and integration with other Adobe apps (Photoshop, After Effects, Adobe Story, Prelude). CS6 is now discontinued and unsupported by Adobe.