More to do with the priority and better maintenance of VB.
This month, I travelled ANVT-LKO by VB and returned LJN-NDLS by Shatabdi.
I could feel the difference between Shatabdi's poor condition/maintenance and VB's A1 maintenance and catering.
VB is becoming a first choice over Shatabdi/other AC class trains (when running immediately in morning/evening slots).