99% of all vodka is made by huge industrial distilleries than then sell it in bulk to other companies. Since multiple spirit companies are buying from the same source, the only way they can differentiate themselves is to talk about how many times they filtered or redistilled the spirit to make it taste more neutral (like nothing). The same with gin, they use the natural industrial vodka, then flavor with botanicals, but the original mash material flavor is nonexisting
There are just a handful of distilleries that actually produce their own neutral spirit, When designing your still, ideally, if it reaches the 95% mark in one pass. What this means is, the vodka contains residual aromas and flavors whether from grain, wheat or potatoes, etc. this actually makes it interesting to drink and unlike any other vodka, in a market that aims for less flavor.
To create a grain to glass distillery, Ideally design your masher, fermenters, and still, are all scaled to process 1 patch at a time, (100kg 250kg, etc. of raw material) there is great efficiency to this and saves extra work and hassles just because some part of the production process wasn’t scaled properly.