As someone who has studied both Esperanto and Indonesian, I'd say they are roughly comparable (although Esperanto is easier). But Indonesian is pretty easy as f

As someone who has studied both Esperanto and Indonesian, I'd say they are roughly comparable (although Esperanto is easier). But Indonesian is pretty easy as far as natural languages go. People wonder why anyone would bother as Indonesia isn't really a major country (and most of their population actually speaks things like Javanese rather than standard Indonesian) and would say learning Mandarin would be more useful. Which objectively it is, but I've also studied that, for a considerably more amount of time than I've studied Esperanto or Indonesian, and with less success.