For people looking at Solana NFT volume and thinking we are down REALLY bad in volume recently, you need to look at the stats that have affected the volume.
Wash Trading -
There has been a great deal of wash trading with NFTs, due to the enforcement of 0% royalties. Having 0% royalties on both a marketplace and a collection gives wash traders the ability to do whatever they like in moving around their capital through listing and selling their NFTs back to themselves. Now, as we have marketplace royalties back and projects are starting to implement Metaplex's new MIP-1 protocol, the wash trading has drastically decreased.
Tensor Airdrop Farming -
Recently, people have been farming Tensor's marketplace through bidding on / purchasing / selling NFTs. This is due to their upcoming airdrop to users who have been using their site. This campaign has concluded recently, and that shows a significant drop in volume since early last week.
Both these key points have played a significant role in keeping up fake volume in NFTs. With both of these gone, we are seeing the true value of NFT volume in Solana.