i dont agree with the tracking that goes along with all of them. i shouldnt be recording my action to a bunch of unrelated companies just so i can give a few cents to a website.
Brave records that data locally, none of it is actually sent to any servers. The only thing they know is an amount of money must go to the websites that your browser viewed. They don't record IP addresses or any personal data.
AFAIK, all tracking (in both Brave and Flattr) happens locally on your device.
Some level of tracking _is_ strictly necessary for a system like this, because otherwise there's no way for the system to know which sites to give your money to.