Because almost everything you've seen as 'working code' started its life as an announcement.
And because to coordinate and discuss future work, there would need to be some announcements.
And because some announcements (based on the persons, e.g. here GvR is involved) or the funding (e.g. here MS is involved) or the specificity (e.g. here 3.10 timeframe is discussed) are more important than others.
>Meanwhile the Erlang people quietly produced a JIT without any advertisements.
Good for them. That's maybe because much fewer care for Erlang (and thus for the advertisements) related to Python (which has a much larger dev base), so the advertisements of the former are posted fewer times and discussed by fewer people.
Not only is it a large user base, but a varied one too. Flask, Django, FastAPI, Twisted...and that is just to name the web frameworks! We have scientific use, research use, cli tools. Perhaps in some cases end users (developers or not) of those tools may not be aware Python is the foundation of said tool.
Anecdotally the Erlang users I've met have been incredibly knowledgeable and in tune with the language features and development. I find that pretty cool.
In my opinion, an argument can be made that Elixir is the most prominent web framework for the language, so developers can just keep up with that and not the language if they wish. Compared to the Python ecosystem. As Erlang inevitably grows in popularity, it too may fragment.
Gist of it: FAANG is very flexible as long as things get done (hinting at really understanding how things work), large corps somewhat flexible between teams (understanding in principle how it works but still being big corps) while start-ups stick to one methodology (sticking what some founder knows, or thinks to know). Brackets are my interpretation.
Based on what I saw in the last year in my current job, that rings true. Agile is the latest shit, so we aoply it to everuthing, from hardware development to ERP roll outs. Not sure if in those two cases it is the right approach.