In my sad experience, you don’t but simply try to avoid getting caught in the blast radius of it failing. Someone approved/supported the project and someone approved/supported the sunk cost that already went into it. Those people have more power than you and they will not like looking bad due to you.
As I see it perfect is the enemy of the good in this case. Rules, official or unofficial, on the “correct way” to do things stifle growth especially when there’s few contributing users. That little extra barrier is enough to keep many people from even bothering at all. You want people to be engaged and excited rather than feeling they’re beholden to a bureaucracy. Or worse beholden to an existing group of power users that control things by being the first or the loudest.
Most every language in use gets pretty constant new releases so is effectively modern. So not sure why the criteria should be a hype language versus simply the best language for the job (performance level, dev time, dev availability, etc.).
Conceptually, this is the outcome of companies owned by those who wish to maximize their investment. Eventually organic growth slows and it’s time to squeeze more juice from the lemons they already have even if they need a hydraulic press to do it. The flip side is that without that investment money these platforms would probably not exist at the scale users are used to. It’ll be interesting to see if the fediverse manages to scale well or not.
In my experience managing a large project comes down to having a consistent process/standards and enough experienced engineers in that language. Remove that and every single language leads to abominations.