“Show us a self-installing virus for a modern Mac. “
You are the expert. Are you staking your reputation on the above statement?
Show us a self-transmitting, self-propagating, self-installing viable computer virus for a modern macOS. . . please. One that DOES NOT require participation of the user or anyone at the computer. In the 20 years of OSX's existence, now macOS, there have been SEVEN candidates proposed for such a virus. ALL have failed for lack of a viable vector.
While the code of these candidates would RUN on OSX, they could not find a means of transmission from Mac to Mac, or from any computer to a Mac. 2013s Clapzok.A was the last candidate that comes to mind, a cross platform 32 bit proof of concept virus that would infect a Windows computer but could not be vectored to a Mac, where could not self-install, but with user help it would run and replicate itself and find other 32 bit executable files in the same directory to infect, but could not spread to another computer unless the user transferred the infected files, making those infected files a form of Trojan.
Yes, Texas, I know there are Trojans out there, in fact there are approximately 148 known Trojans in eight identified Trojan families. Every single one of them will be identified by the OS itself which will warn the user before it will allow the user to continue to download, install, or first run the Trojan, requiring that user to provide an administrator's name and password to continue the dangerous behavior. Trojans are NOT, by definition, true computer viruses.
I am also aware of malware that can be installed through the USB or Thunderbolt ports from poisoned devices designed to alter the I/O or even System firmware. That is little different from a Trojan as it requires the action of a user. Apple has blocked any firmware or specific core system component changes by adding a passcode which must be input from the keyboard that is different from the admin password before any change is permitted.
So, Tex, where is that viable macOS/OSX virus you think exists? I'd be really interested in seeing it.
By the way, I manage an installation of over two dozen Macs in a business environment, all without antivirusware for over twenty years. Not a single malware has ever invaded those Macs.