Very true, I've just met a woman in a tram that speaks Esperanto. It is obviously still its niche thing, and is not catching on outside of the realm of #poliglots, however there is also Slavic Esperanto, which is more for the Slavic population.

Language always searches for the path of least resistance, and for the moment because of world power and economics, that's English. I could are something like a Chinglish language working well as two rivaling languages. But that's just a guess.

Furthermore, the need of language learning seems to be more of a nice part time hobby In the future, by looks of AI translation speed nowadays. So you only need to be good in one specific language customized to you, and then be familiar with concepts, which can be translated in all kinds of forms between two people.

Saluton! That's all the Esperanto I know...