Why do all audio forums on the internet seem "dead" ?

Well, if you speak of Audiogon, those of us who have been around for a number of years, know that Audiogon shot themself in the foot a few years back. Although this site now appears ’slicker’, it just ain’t the same. Too much of this site’s sale’s ads are from dealers. This is a much larger percentage than prior to Audiogon’s changing ownership. It is sad, as it does seem that the ability to sell a good item, has decreased markedly since 2011.

In addition, I am not sure what 'you' mean by Classic equipment, but there is not lack of it out there.  The problem, now, is that it's quality is acknowledged, and the prices reflect that.  I was having my tube amp repaired, and I was at my 'repair guy's' place last week.  He purchases, and refurbishes classic McIntosh tube gear.  By the looks of things at his place, he may have cornered the market of Classic Mc equipment. ;)