Can we please stop propagating this accusation? Alright, sure, maybe LLMs overuse the em-dash, but it is a valid topographical mark which was in use way before LLMs and is even auto-inserted by default by popular software on popular operating systems—it is never sufficient on its own to identify LLM use (and yes, I just used it—multiple times—on purpose on 100% human-written text).
Sincerily,
Someone who enjoys and would like to be able to continue to use correct punctuation, but doesn’t judge those who don’t.
I feel the emdash is a tell because you have to go out of your way to use it on a computer keyboard. Something anyone other than the most dedicated punctuation geeks won't do for a random message on the internet.
Things are different for typeset books.
Small group a capella is slightly more viable, but it's very "amateur coded": even very good a capella groups perform a lot of covers, and rarely stick with one genre. They perform whatever they want, which is often also things with commercial appeal, but isn't ideal for long-term musical identity building.
Take Rajaton for instance. Extremely technically brilliant, but their own compositions are a relatively small part of their repertoire (and still more than most a capella groups!). Pop music covers and Christmas music are obviously a big part of what makes them commercially viable, in addition they perform commissioned work from acknowledged choral composers (Mia Marakoff, Michael McGlynn). When they do the occasional album with good stylistic coherence and their own compositions (like 2016 Salaisuus) it doesn't look like a commerical success.
That really depends where you live. In Vienna you definitely get all-professional choirs of that size for instance.