I worked one summer at a small dairy packing plant, where I could observe the same thing with cottage cheese. They made a big huge vat of the stuff, and it was packaged into tubs with several different brand names on them.
I have done a salt tasting before. It was at a cooking class I took. They poured out about 10 different kinds of salt - from Morton’s to Kosher to Sea Salt from various seas to French Black Salt (really more of a grey color). There really is a difference in taste between them.
I personally go for flakey salt. Flakes seem to dissolve faster and add more a depth to whatever you’re adding them to. I buy Sea Salt that comes in flakes.
Of course, my favorite way to add salt to something like a tomato sauce is to just throw a couple anchovies in. Not fishy at all - just a deep salt taste. Yum!
I think I remember hearing they add it to the salt they use in making the french fries to brown them, but I have NO IDEA why they’d use it in the regular packets.