Tok Pisin in New Guinea is based on English and it works well in a country where every village speaks its own language. It's similar to Pidgin which is widely used throughout the Pacific islands.
Swahili also counts, across different parts of East Africa.
English itself is one of the easier languages for non-natives to learn, believe it or not. The irregular spelling is by far the hardest part. Me but can no speaking goods English we understood be can, though! Foreigners can speak atrocious English and still be understood. Which is an advantage many languages such as French or Chinese don't have.
So there's no real need for Esperanto. Most of the world already communicates in broken English, for example when a Hungarian and Indian do a business deal, they aren't speaking in Hindi. A simplified English is the international language we have now.