I mean, look at Opensea volume, it still did 2.5b last month. The nft "hype" hasn't really died at all to be honest. Yes, there were grifters like with any gold rush, but to say it's astroturfed is just totally laughable.
Is it possible to tell how much of that $2.5b was wash trading?
I assume $2.5b.
There's some wash trading, but it's very little. Chainalysis publishes reports on stuff like this regularly.