Well no. Valuations are based at least in part off discounted future cashflows at a very basic level. If projected cashflows drop enough due to bad economic conditions the value of everything will drop. If you think at a basic level there is less capital to return to shareholders via buybacks or dividends.

Also the fed finally stopped propping up valuations with QE, money is leaving the economy (about damn time).

FWIW VC/PE/some other private stuff isn't actually down yet at least not on paper. But this is bc they are not marked to market very often at all. The reason activity is still good is bc valuations are way down, like half in a lot of cases.