For many creators, CS6 Extended (version 13.0) was the "holy grail" because it was the last major release available as a —meaning you could buy it once and own it forever without a monthly fee.
CS6 arrived at a crossroads for the technology industry. Desktop computing was shifting from pure CPU reliance to heterogeneous computing (utilizing both CPU and GPU), and software distribution was on the verge of shifting from perpetual licensing to Software as a Service (SaaS). CS6 was the last version of Photoshop to be sold via a perpetual license (excluding the "CC" rebranding of CS6 that followed shortly after). Consequently, v13.0.13 is often viewed by purists and industry veterans as the definitive version of "classic" Photoshop—stable, feature-rich, and fully owned by the user. adobe photoshop cs6 extended 13013 original work