Ask HN: How to find non-popular blogs and forums?

It used to be possible to use Google Search operators to search narrowly for something you were interested in, and then you'd find niche specialized forums, and random blogs with like 5 active readers.

I feel like this is no longer possible. I cannot find my own blog, like, at all. I'm not even indexed. What do you use simulate the web search experience from, say, 15 years ago?