How can bitcoin become fungible?

I’ve been a bitcoin advocate since 16’ and accumulating for years. The only real issue I see with bitcoin as a whole is it’s fungibility.

How do we go about removing the ‘past’ of bitcoin transactions. Let’s say your bitcoin goes through:

Drug lord -> stripper -> gas station -> gas station employee -> you

How do you remove that it ever was in possession of the ‘drug lord’

This is an issue because we are already seeing some companies ban certain coins from addresses that were associated with the Silk Road etc.

Yes you could make a argument that cash is traceable but it is much harder to do and tedious and not nearly as accurate.

This is just a discussion thread, if I’m completely wrong please explain!!

Thanks ????