I was curious because I tried to do a test search using site:https://piefed.social into google and didn't get many results. If its not indexed I'm not complaining, to me that has plusses and negatives. I feel the internal search is actually useful compared to something like reddit.

Using Duckduckgo, I can find old piefed and lemmy posts

A very small number of pages are indexed but Google seems to be having a hard time finishing the process. I just clicked around a bit in the Google search console, maybe that'll unclog it.

Each user can control whether their content is visible to google so it'll be all over the place even in the best case.

Is that what the "My posts appear in search results" setting does under settings?

Yeah