Yes agreed.
Both Bitcoins and ETH tokens can be "tainted" and that taint takes for ever to "diffuse" in the chain.
This makes some Bitcoins/ETH less valuable than others.
For example, most valuable Bitcoins are newly mined coins (they have no history), whereas a - say - Bifinex hacked Bitcoin carries a pungent smell.
Much easier said than done:
- it costs money
- most tumblers aren't safe at all (who's to say they aren't operated by the govt or that they don't keep logs)
- in some cases, you might not get your coins back at all
Shouldn't you expect that most people paying to use tumblers have a reason to do so, and thus the vast majority of coins from tumblers are tainted as well?
What does "individual financial sovereignty" mean though? Money is only useful as part of a social system and therefore requires some sort of social contract.
I'm all for privacy when it comes to storing and transferring amounts that are consistent with personal consumption. I'm not in favour of letting people move millions or billions anonymously unless they are willing to renounce all protections they enjoy under the law.