My recollection of my Winstons and Thunderakys was that the volumetric density was a lot less than my EVE cells, Maybe part of that is the thinner shell but is there another explanation?
Thinner electrodes means thinner graphite on anode, thinner LFP on cathode. It reduces ion diffusion resistance at high current. Thick electrodes decreases cell current rate where layer ion starvation becomes significant. Thicker electrodes and ion starvation increases cell loss at high current, with greater terminal voltage slump at high current.
The AH capacity of a cell is based on amount of LFP in cathode and corresponding ratio amount of graphite in anode, Thinner electrodes means to get similar capacity there must be more layer area and/or more layers, with more corresponding copper and alumimum foil along with additional separator material soaked with electrolyte. All this cost more to manufacture cell.
The extra copper, aluminum foil and separator/electrolyte material takes up more volume and adds weight.
Highest peak current cells have about 20 um thick electrodes. Fat electrode cell design, to maximize AH's for given size and weight, are in the 120-150 um thickness range. Copper and aluminum foil is typically in 20-25 um thickness range.
My guess for Winston cells based on their peak current capability, the electrodes are in the 50-75 um range.
EVA design is based on 'AH' number sells cells so maximize AH at lowest manufacturing cost. Okay, but should not use them above 0.5 CA continuous discharge current rate. With 120-150 um electrode, layer ion starvation starts to get significant above about 0.5 CA current rate.