Does Total AV offer added protection not already offered by or included in Apple products ?

Apple products unlike Windows have the kernel protected and in its own sandbox.

That said, viruses and malware are typically localized. What good anti-virus tools do is keep up with these localized attempts at infections. Many of the software that is malware on the Mac comes in the form of programs that purport to be optimization programs, which are not, that people download off advertisements on the web, and/or get misdirected by bad email links.

I only use these tools in my malware removal process manually, and only after backing up my data:

Etrecheck to see if there are any added Daemon applications that belong to known fake optimizers like Macpaw, Zeobit, Mackeeper, Advanced Mac Cleaner, Cleanup tools, older versions of Chromium, known torrent installation tools which typically distribute pirated software, and applications that the user is unaware how they got on there.

Devon Technologies EasyFind in safe mode to remove those tools, their preferences and extensions.

Reggie Answorth AppDelete to remove applications whose residual components are unknown where their locations are, and the developer does not provide an uninstaller.

Avast full system scan.

Check for installed browser extensions that serve no useful purpose. Most adblockers are OK.

And lastly if someone is running Chrome, I check chrome://policy to make sure no one has put in a policy that has a funny name in it.

This process I charge $150 for, especially for people where the process is typically beyond their capability to manage without being overwhelmed. I would check TotalAV's reviews to verify if it does everything Avast can do and Malwarebytes can do.

Many of the anti-virus tools only keep a partial update of all the malware that can be attached. Never run more than one malware tool at a time. Malwarebytes has been one of the only ones that can be running together with others.

No.