What stays private, and what does not
Worth being exact here, because privacy claims are easy to overstate.
What nobody can see
Nobody can see that the payments to you are connected. Each one goes to a different address, and there is nothing on chain joining them together. Someone watching your link cannot follow the money from there.
What is public
It is public that a payment happened, when it happened, how much it was, and which address received it. The chain is open to everyone, which is the point of it. Amounts are not hidden.
What we can see
We can see your username, the public keys behind it, and the address of whoever visits. We never hold your keys, and we cannot move your money or read your balance.