I mean, a jelly is just broadly any thickened sweet goop (doesn't even have to be fruit, and is often allowed to have some savoury/umami, e.g. mint jelly or red pepper jelly). Usually a jelly also is relatively clear and translucent, as it is made with puree / concentrate strained to remove large fibers, but this isn't really a strict requirement, and the amount of straining / translucency is generally just a matter of degree. There are opaque jellies out there, and jellies with bits and pieces.

Ketchup has essentially all the key defining features of a jelly, technically, just is more fibrous / opaque and savoury than most typical jellies.

But, of course, calling a ketchup "jelly", due to such technical arguments, is exactly as dumb as saying "ayktually, tomato is a fruit": both are utterly clueless to how these words are actually used in culinary contexts.