Not for work, not for promoting your new project. People that write informational blog posts about their opnions on things, or projects they did with no monetary pursuit.. why?
I mean it's a lot of work. And broadly speaking, you're more likely to get negative feedback than positive. And more often than either of those, you'll be ignored entirely.
What's your motivation to set aside 3-300 hours writing something up?
Ask HN: Is maintaining a personal blog still worth it?
https://news.ycombinator.com/item?id=42685534
Why I still blog after 15 years
https://news.ycombinator.com/item?id=41646531
Advice for a friend who wants to start a blog
https://news.ycombinator.com/item?id=42872276