basically they hijack dns resolution to return does not exist errors when requests are sent to the tracking systems. highly effective, but also many sites are negatively impacted by them because no one codes for failure in the web industry.
it can be fixed but would require herculean engineering efforts, the biggest problem atm is the canvas. most of the other things can be fixed via defaults that are returned to the webapps unless explicit permission to access them is granted. like there is never a reason to return errors for session storage if its disable. just return a memory implementation that doesn’t persist beyond the window life. little changes like that would go a long way to removing the bits of information.
there are well known distribution lists that people add servers to that these things periodically fetch and use to perform the blocking.