I have not conceded anything. Many crimes would be perfectly unsolvable if everyone did everything perfectly, and yet.. You are again using "logically impossible" while insisting on a very specific condition, "not knowing all inputs into the laundry", which is very much solvable to a high degree of certainty - CM mixes so hard that their addresses are all connected to each other - I just need to send them a single transfer, watch it tumble, then connect the dots, and then list all transactions leading into that giant hairball of connections. Just read the Justice Dept complaint against CM - it has an extensive inventory of specific customers and crime proceeds, using "Company A [..] tracking approximately 118,500 bitcoin addresses associated with ChipMixer". Now how would they do that if it was so logically impossible?

And why would having a private key to an output address that no one else has touched be an evidence to a crime? They probably only delete them after the user has transferred the funds out, if they even bother.

I don't know why you are so bought into Bitcoin privacy specifically, but it holds as much water as the privacy statements in the App Store - anyone with sufficient motivation and data analysis skills can poke right through it. Monero is likely stronger, but if it can't be cracked, then as soon as it becomes big enough it will get blocked.