The more your browser acts to hide your behaviors and limit tracking, the more unique your fingerprint is. The most private browser setup is one which appears to be identical to all the other traffic in a non unique way, or noise. This definitionally lacks information for tracking.
Also security flaws and tracking exploits need to be constantly patched.
This is a fundamental tradeoff for privacy. Using more obscure browsers can (not always) then expose you to behavioral fingerprinting because they look different and react to web pages differently.