attract users who predominantly speak English as their primary language
I never understood this argument. Why do you think it’s important whether English is your primary language or not?
People in developed countries often speak English pretty much perfectly (and know the difference between their and they’re).
If you’re going to a web site with a mixed audience, you’re gonna use English, and if you’re going to a local one, you use your local language. No big deal?
Native English speakers have the advantage of not needing a different language to speak to their locals, but that’s all.
If somehow everyone agreed that Esperanto will be the default internet language, you wouldn’t expect the majority to be native Esperanto users.