Could you cite studies and give examples?
For a real world example sugar was first synthesized in 1953 https://en.wikipedia.org/wiki/Sucrose#Chemical_synthesis
Carbohydrate synthesis is also a well studied field. https://en.wikipedia.org/wiki/Carbohydrate_synthesis
Many vitamin additives today are artifical. And of course artificial flavoring has vast commercial adoption. In the case of McDonald's french fries this was used to dramatically reduce the amount of saturated fat while maintaining the beef flavor - they are no longer deep fried in beef talow.
We can't yet recreate the texture of a pepper, but we can certainly create a synthetic smoothie with the necessities of life. Organic chemistry is a rich field of study.
Of course there are a few simple compounds which are edible, but most artificial additives are extracted and processed from grown inputs, and this is susceptible to unexpected health problems as happened with exposure to trans fats for decades - now banned.
> we can certainly create a synthetic smoothie with the necessities of life
That is a low bar - being capable at any cost to synthesis a smoothie with 'the necessities of life' including growth? good health? You didnt even reference that.
The food landscape is filled with pseudoscience, and whether a compound is synthesized or extracted is more of an economic decision not a scientific one.
Small amounts of almost anything can be synthesized at great expense, but you should have provided an example of a wholesome food which would not be completely uneconomical to synthesize (and purify) in bulk, to support a claim that there exists such a potential economic possibility. Even how much for example, it costs to synthesize food grade sugars would be a start on showing your advice on this subject is grounded in reality.