First I am not a historian, I apologize if that is not allowed I am just a Dietitian with a passion for the history of food. I would defer to an answer from a historian on this topic.

Much of my information will come from the article "Making a global sensation: Vanilla flavor, synthetic chemistry, and the meanings of purity" by Nadia Berenstein.

A large part of why we enjoy the flavors that we do is hard to quantify, but the vanilla beans were used in the cuisine of many cultures in the region notably in the drink chocolatl which was served to Cortez by Montezuma. Many of our spices that now are common were a rarity across the world. While vanilla was incredibly saught across the world, it wasn't until it was artificially created that the ubiquity of vanilla became solidified.

The early days of its use in European cuisine were primarily as a component of chocolate which enjoyed popularity in the seventeenth century. Though botanists throughout Europe attained specimens they found their efforts fruitless without the "Melipona" bee that pollinates the flowers. The stubborn plant was eventually transplanted to the French island of Bourbon.

The transplanted vanilla orchid would remain fruitless until Charles Morren a professor of Botany first successfully pollinated the orchid artificially. A method of hand pollination was also developed by a slave named Edmond Albius on a plantation in Bourbon. As demand increased in France for delicacies like vanilla chocolate and vanilla ice French colonies began to expand cultivation in the Indian Ocean, West Indies, and Tahiti, as well as Dutch plantations in Java and German East Africa.

Vanilla requires a labor-intensive process that requires beans to be dried, sweated, and cured which that sometimes may require months of daily work and close attention. Fortunately, the decades of vanilla planifolias colonization of the globe coincided with rapid advances in synthetic organic chemistry.

Vanilla was not the first synthetic flavor (this belongs to various fruit flavors), but it was the first luxury flavor to be produced synthetically. In 1874 German Chemists Ferdinand Tiemann and Wilhelm Haarmann synthesized vanillin from coniferin. This discovery was widely reported and confirmed by Karl Reimer who derived it from creosote tar. Vanillin did not enter the market cheap listed at $1,500 a kilogram considerably more than the cost of an equivalent amount of vanilla beans. New innovations in the production of synthetic vanillin lead to a drop in costs. New manufacturers across the United States and Europe challenged French and German companies' dominance of the market caused the price to plummet from 560DM in 1896 to 126DM in 1897.

By 1900 the US saw a rapid increase in the sale of both vanilla beans and synthetic vanilla corresponding to the expanding role of sweet foods in American life. Technological innovations created the ability to manufacture ice creams, chocolates, and other confectionary items on a large scale at a low price. Both artificial vanilla and vanilla beans prices continued to decrease throughout the early 20th century. Sugary vanilla flavored treats became everyday indulgences due to the wide availability of cheap sugar and artificial vanilla.

Today over 95% of the vanilla products on the market come from artificially produced vanillin.

Source:

Berenstein, N. (2016). Making a global sensation: Vanilla flavor, synthetic chemistry, and the meanings of purity. History of Science, 54(4), 399–424. https://doi.org/10.1177/0073275316681802