I was referring to the fact that Google solved the search problem and so made it far more likely that people would happen across forums that contained subject matter of interest to them.

I agree that that was an important factor in driving worthwhile discussions to the web.

Another important factor is that web client software became ubiquituous whereas news client software had to be downloaded and installed before a person could read the newsgroups unless of course the person relied on a web interface, the most prominent and important one being Google Groups -- but like I just said, Google Groups had serious deficiencies.