Hi @TheRookieGB,

To answer this question, I think we need to analyze how the threat landscape looks like for macOS and the role Antivirus for Mac plays in this context.

Naturally, macOS includes built-in antivirus technology for the signature-based detection and removal of malware, and there's a strong belief among its users that it doesn't require any additional protection. For years, Mac users were told they were safe, and I think this statement somehow created this misconception that we face today, that only Windows computers need antivirus protection.
But how exactly do people reach this conclusion? And why exactly are Macs considered immune to threats?
Well, for the most part, it's like you said, the operating system is based on the UNIX architecture. This system is known to be more secure than others and especially less attacked by hackers because it’s not as popular as Windows. It’s going to cost the average hacker more to build Mac malware than Windows-based malware.

In some way, I believe Antivirus for Mac is "challenging" users to rethink their security, which until recently had a bulletproof status. In any case, mac-designed malware is definitely not something new..

Look, a safer operating system does not mean that it cannot get viruses. Vulnerabilities in third-party software essential for web browsing (browsers, Java, Flash, Adobe) can be exploited by malicious code. Adware and ransomware are currently the most frequent infections that target Macs, and will remain one of the most important trends. On the other hand, phishing attacks cannot be prevented by the operating system. For its part, Apple was criticized for not reacting quickly enough to security vulnerabilities. For example, the Rootpipe vulnerability discovered in October 2014 was patched only 7 months later, in April 2015. But that happened over a decade ago.

Back to your initial question now, I think Antivirus for Mac excels as complementary security if you will, or an additional layer of protection on top of the excellent defenses already found in the macOS. Because they are strong, there's no doubt about that. If you go through the antivirus feature set (and if you are already familiar with its Windows counterpart), you'll notice that the security technologies available on Windows are not replicated for macOS (but the software's focus is to protect the Mac in real time against infections, and Bitdefender obtained excellent results in time on the AV-Test independent tests conducted in this area).
Not replicating the same technologies available for Windows happens for a reason: macOS does not require the same amount of extensive anti-malware modules as access is much more restricted to any third party (not only including possible malicious apps/files, but the same restrictions apply to third party software manufactures such as Bitdefender. So, even if as a cybersecurity vendor, you could actually do more to boost security in some areas, implementation is not possible as Apple holds primary functions in that area for themselves.

Regards,

Alex