For me, transactions are traceable because blockchain has a record of all bitcoin transactions, and these transactions are in public that anyone can see. Also, all miners will confirm your transactions to another miner to confirm it. That's why its called peer to peer. But except names, you are given a bunch of code/ address so that you have a unique name. But most of the local exchange has KYC and gives you only one address, so if you transact using their wallet, they can identify you.