But sea salt is better than salt. and cider vinegar adds additional flavor to regular vinegar, more depth.
I know people like you and Ash hate change/progress with a burning passion, but the reality is that sea salt and cider vinegar crisps are a massive improvement on the traditional version.
Salt is salt is salt. It's all sodium bleeding chloride, mate. Just bigger crystals ground down to the same powder they spray over the crisps. Acetic acid tastes pretty similar whether it comes from apples or grapes. FWIW cider vinegar was the only vinegar on the shelf back in the day anyway, so I doubt Smiths Crisps used something different.