In Windows not longer needed, due to the experience through decades beeing the most atacked OS, nowadays the Defender among with the sandbox system is one of the best AV out there (independent AV Test). This certainly was bad for the traditional AV, which are now searching other victims, passing often to shady methodes to promote their product. Windows is (by default) a privacy nightmare, but in question security is currently pretty strong protected (at least one thing well made). Maybe also the reason why hackers now are more centred in Linux and Mac.