While (human) vision is 3 colors, reviews of visual arts obviously can't just describe the colors of the thing. It also has shape, depth, style, etc.
Food reviewers don't note the levels of salt, sour, etc. They describe flavors and textures and parings.
But also, I don't buy that taste is just the composition of 5 components. This sounds like a reference to that diagram of the tongue we've all seen. It's as complex as scent is. There's no way you can define the taste of cinnamon by specifying some sort of 5-tuple.
I believe he is correct. The misunderstanding is from the old chart that showed certain tastes were only detected by certain parts of the tongue.
It’s still true that we can only taste salty, sweet, sour, bitter, and umami. All other flavor complexities come from scent simultaneously giving us information. It’s why everything tastes so boring when you have a head cold.
Think about this, suppose you're on a Zoom call and you want a person on the other side of the call to match a color that you're seeing. You can say "make it more blue", "make it brighter", "shinier", etc.
You can get pretty close to what you're seeing this way.
Taste is just a combination of 5 basic tastes, vision is a combination of 3 primary colors, etc.