It's maybe worth doing if you can think of a niche that won't be overwhelmed, but will still prove relevant to enough people. I get the impression that Medium is trying to extend its cultural reach beyond the USA (which to my mind is a blinkered perspective the platform and its curators still have).

Two of this last batch of 10(?) additions were from that angle - Iberospherical and A-Culturated, and they had recently added Japonica as well.

If you set something up now, you can just largely self-publish, while leaving submissions open without actively promoting/recruiting, and build it up very slowly. And then if you decide to go for Boost status in the future, you have a body of work and core of writers to present a convincing pitch from Day 1, and have a flow of stuff to nominate.

Maybe the 'English-speakers not from the USA/UK' angle might be of interest. Reflections on distinctive idioms and slang, experiences of being misunderstood/discriminated against/generalised about because of accent and language in the self-appointed 'owners' of the English language. The whole 'countries divided by a common language' idea. Just a thought.

Sadly, the way things stand at the moment, being a Boost nominator is the only way to make any worthwhile money from this platform, and I very much get the idea that they are really committed to it, especially as a defence against AI stuff. Whether it is viable to maintain the current economic model, I don't know - it doesn't stack up for me. But being able to say you are the 'founder of a designated nominating publication on a content platform with 1 million paying subscribers' is probably worth it for freelance CV points anyway.