The way I remember, when flow was introduced, you had to do small changes to 3rd party dependencies your code might have had to make them flow-compatible.
With typescript you could just write a type definition file for any 3rd party library, so you could essentially make any 3rd party dependency "typescript compatible" without needing to change its code.
This small difference made a huge impact for adoption. Eventually flow also got that feature but by then the adoption difference was already too big.
But don't hold yourself too much if you think you're not too knowledgeable about something to present about it.
You may be deterred by watching some talks where the presenter seems awesome and seems to know so much more than you. You don't have to be the top expert on a topic in order to know a few things worth sharing.
With typescript you could just write a type definition file for any 3rd party library, so you could essentially make any 3rd party dependency "typescript compatible" without needing to change its code.
This small difference made a huge impact for adoption. Eventually flow also got that feature but by then the adoption difference was already too big.