Monero has lost ~90% of it's value vs. BTC since last September
Uh, no. You are misreading something.
You can implement the exact same distributed and trustless mixing mechanisms in wallets that live on top of Bitcoin
No you can't. It is totally different cryptography at the transaction level, and would require at least a soft fork, but that is very messy and far more complex than any existing or proposed soft forks, meaning it has essentially zero chance to happen in practice. It could and probably will happen on a side chain, but that raises various other issues.
There are other differences like an actual deployed (and somewhat stress tested) mechanism for managing the blocksize without a hard limit.