I am a long since ex- Esperantist who is not keen to defend the language and movement, but your post is way off the mark. Esperanto was a decently big fad in the former Eastern Bloc, because learning it allowed you to correspond with exotic foreigners and maybe even get visa invitations to go visit other countries (for Esperanto events) you otherwise might never dream of. Sure, some of those countries are now much more prosperous and developed, but they weren’t then. My memories of European Esperanto congresses decades ago are a lot of Ukrainians, Russians, Poles, Hungarians, and Romanians clearly on the lookout for a Western European spouse, or stuffing their suitcases with local goods they could sell back home.
Similarly, West Africa has always had its own local Esperanto scene, for roughly the same reasons of being able to get visas etc.
There was a lively Esperanto community in Yugoslavia, which was a non-aligned country that had more travel opportunities, but still wasn’t a "rich Western country".
You hail English as "able to give the underprivileged greater opportunities". But the reason for that is that English is more widely spread, and dominant in the most wealthy areas. Which is... well... imperialism.
It sounds like you're simply dismissing Esperanto as a niche hobby for a handful of white nerds. Which, in terms of practical benefit, might well be accurate. But it is BIZARRE to invert the definition of imperialism to over-state this point.
Anecdote: We had a Japanese Esperantist visiting a local meeting in the US and of course asked if Esperanto is really ten times easier than English for Japanese speakers.
His reply (in Esperanto): "No. It's a hundred times easier."