There are niche ketchups. I buy them from time to time - since regular ones (including Heinz) have too high sugar content, and also I don't like the taste of Heinz one. So yes, there are different ketchups - and there are different soft drinks too, by the way.

Whole Foods has over 10 brands of ketchup: https://www.wholefoodsmarket.com/search?text=ketchup including their own "365" label. It suggests to me if everybody were buying Heinz, they probably wouldn't bother doing their private label?