.....what? What forums have dissapeared from Google? I get and search forum results all the time. This is not including of course the forums that have gone private or purposely delisted themselves
I can't surface them at all for non-programming sites. Occasionally automotive, but it's still mostly AI generated made for adsense junk. I can use site: filters on sites I know about, but I can't find anything on a page I don't know that way. Your filter bubble may be different.
