Bitcoin fungibility

Is bitcoin really completely fungible? What about tainted bitcoin that government chain analysis labs flag as involved with illegal stuff or whatsoever. Doesn't that make these btc less attractive or valuable compared to newly mined or "clean" btc? Fungiblity is a core property of good sound money and I think it's at stake. Centralized exchanges with their kyc make this issue worse and worse. I heard that there might be solutions like multiple coinjoin, is this doable still after the whole attack on samurai and wasabi shutting off their coinjoin service? What do you make of this overall?