That's Bitcoins problem now isnt it? Bitcoins privacy issues are it's own. Has nothing to do with transactions made on Monero.

Second, you actually can do this thru p2p txns on Bisq, or atomic swaps via UnstoppableSwap or BasicSwapDEX. Several more on the way with Haveno and Serai later this year. Better than even coinjoins as there is no way for any third party to know a swap even occurred by looking at either blockchain. It's obvious to see when Bitcoin has been coinjoined.

Also, it doesn't have to be Bitcoin. 

You can buy Monero directly with fiat p2p with several options above, or LocalMonero/AgoraDesk. There are also cheaper and more private crypto you can go thru like Litecoin and MWEB. 

 How does the swap leak privacy? There is literally no way for any third 
party looking at the chain to know Bitcoin moving from address A to 
address B was actually a swap for Monero.

Impossible lol? Seems like you have never done it or don't know how because it is easy as shit. There are always users on either side of the trade. I just showed you several ways to go XMR <-> Bitcoin/crypto or XMR <-> fiat p2p. I can hand hold you thru the process if you really want.

Yea, you can use fiat cash locally if you want and it is useful. But you can't use fiat cash digitally. And digital fiat, crypto, and Bitcoin aren't private.

Monero is essentially the only thing that is digital and gives you strong privacy without compromising sovereignty.