That's like saying every currency note is traceable because it has a serial number. If someone hands you a dollar today can you trace it starting from where it was printed to everything it was used for until it eventually got into your hands?

Yeah you can look up bitcoin wallet IDs on the ledger, but you can also generate an unlimited number of wallets, and pass coins in any combination through any number of mixers and tumblers, and exchange it between multiple currencies (some of them truly untrackable). If people or organizations want to stay anonymous in the crypto ecosystem they can very easily do so.