Created by Ludwik Leizer Zamenhof in the late 19th century, Esperanto is to this date the most successful example of an artificial language. In theory, if it had succeeded in the way that Zamenhof had hoped, today the translation profession would be obsolete. So, why did it fail, and could it be revived?
Esperanto has many positive qualities. Zamenhof created it to be easily learnt, with no irregulars and minimal vocabulary; being on average 5-15 times quicker to learn than other languages. As it is designed to be learnt as a second language, alongside the national language of a country, it doesn't take away from a country's culture or original language, simply creating a way for people all over the world to communicate with each other.
Despite originally gaining immense popularity and even being considered as a choice for the official language of the League of Nations (the decision was vetoed only by France), a variety of factors led the language to decline in use and recognition. One of these factors was the timing of its creation: the rise of nationalism in the 20th century led Esperanto to be banned and even punished in countries such as Nazi Germany, Franco's Spain and Stalin's Russia. The other, arguably more damaging factor, was the English language. English already had millions of speakers, and post-WW2 was becoming an international language due to America's economic dominance and imperialism, and the rise of Hollywood. These factors, amongst others, meant that today Esperanto speakers total, at most, a mere 2 million.
However, the language's popularity is growing once more, with Duolingo having released an Esperanto app, and the language being one of the most overrepresented on the internet. So, we have to wonder, could it actually become the world's second language?
The answer is probably not. Although the concept makes total sense and would certainly benefit politics, business, travel, and general worldwide communication, the reality is that at the moment there is very little incentive to learn it (bar a love of languages). There is no country or culture attached to the language, and its small number of speakers creates a vicious cycle whereby people think that there are not enough speakers to make learning it worthwhile, so they choose more widely spoken languages, such as Mandarin or English, so there continue to be a small number of speakers, and so on.
There would have to be an international, unilateral decision that all countries must teach Esperanto to children as a second language in schools for Zamenhof's dream to be truly realised, the reality of which seems unlikely. So, for now, translators are safe from Esperanto.
http://www.bbc.com/future/story/20180110-the-invented-language-that-found-a-second-life-online
https://www.interlex.eu/does-esperanto-mean-the-end-of-the-translation-business/
https://www.theeuropean-magazine.com/anna-polonyi/6399-the-rise-and-fall-of-esperanto