By default on a Mac, "smart quotes" is enabled that turns "" into “”. I don't think that's a sign of an LLM. I believe Microsoft Word on all platforms does this too.

Interesting, did not know that. The writing feels undoubtedly LLM generated to me regardless, which is a trend in their other blogs too. https://fireborn.mataroa.blog/blog/if-you-recognize-me-in-pu... is the worst offender.