This is all from the point of view of a decentralized, p2p, no kyc exchange. If you pay for bitcoin with an interac e-transfer, I have heard the bank has no idea where the money went, or at least does not know you bought bitcoin. Is this true?

Once you have bought the bitcoin, do the banks and the government know you own bitcoin? Do they tax you on that?

When you buy monero with bitcoin, do they know you now own monero, or are they just guessing that you do, in other words do they have proof that you bought monero? Do they even know you bought monero? I am eagerly awaiting an answer as I think these are fundamental questions.

Also, what is the advantage of using Bisq over other decentralized, p2p, no kyc exchanges.