If by 'money laundering' you simply mean transacting in a way that is mostly anonymous, you can do this today just be using cash, finding someone else with cash, mixing your bills together, and none of that is either wrong or illegal.
If by money laundering you mean committing a criminal act and then hiding its financial traces, then that is only one possible use of tumblers, but there are other legitimate uses.
It's sufficiently anonymous for most people to just spend the cash they have. You didn't get the cash from D. B. Cooper, right? So nobody's watching the serial numbers. You just spend it.
It's only Bitcoin where that isn't an option.
Edit to be clearer about what my point is: cash has a moderate amount of anonymity, with practical limits. If those practical limits are a problem for you, you probably are covering up a crime. Bitcoin, however, has no level of anonymity between "everyone can see everything you spent" and "covering up a crime".
All the terrible privacy implications of using Bitcoin that you've described are true. The conclusion "so therefore it's okay if I launder money" does not follow. You could instead not use Bitcoin.