The trouble is that “tastes good” isn’t a blank canvas. It’s built on hardwired signals plus learned associations. Our basic tastes evolved as nutritional indicators: sweet signals energy, umami signals protein, bitter warns of potential toxins. And our brains are rather insistent about finding flavors more pleasant when they match patterns we’ve already learned are safe.
Jell-O actually proves this rather than refuting it. It succeeds because it hits that hardwired sweet preference, not because it invented some novel taste dimension. A truly new taste that doesn’t map onto the existing five basics would likely register as “off” rather than delicious. Your brain wouldn’t know what to do with it, nutritionally speaking.
So you’d have to either work within those existing taste channels while creating novel combinations and textures, or somehow condition people to associate genuinely new sensations with safety and reward. The latter is slow going. We’re quite literally built to be suspicious of unfamiliar foods.