With today statistical analysis methods is trivial to track big flows through various block chains, even if some of them are totally hidden. And they only get better by the day, with your traces sitting there like a duck.

And you don't need to be 100% certain, it's enough to get a pool of suspects which then you can analyze/surveil with other methods.

How about monero?

Bitcoins's high transaction costs and low transaction rate prevent that from working.

Because you trust yourself, you don't have to outbid everyone to get your transactions on the blockchain immediately.

You still need to get on at some point. Plenty of people are willing to wait a few hours to get confirmed so the price never hits zero. Further, even if it did work you would make your mixing transactions stand out more while also vastly lowering the number of them.