No English is not at all a fully neutral playing ground. It's in many countries a strong differentiator between rich/elite class and poor people. It's already the case in a big part of Europe and even more present in the rest of the world. For most Europeans, Esperanto can be learned quickly as grammar is very simple and vocabulary share a large root with European languages. On the other end, English is a big mess of exceptions (grammar and pronunciation). This requires extensive training to reach a basic level.