I don't think that's true at all, except for the most generic of grocery stores. Case in point: https://www.wholefoodsmarket.com/search?text=ketchup

There are also an innumerable amount of other sauces that include tomatoes and can be considered variants or ketchup-adjacent.

Naturally on the Internet there is an infinite variety. But using that Whole Foods site to filter the list to what's physically available at stores in my area, it reduces down to a list that's more or less Heinz and Heinz-like.

I find all ketchup that isn't Born Ketchup pretty much disgusting.

I wasn't counting on finding anybody else who loves Born on HN, but here you are :)