Nobody said that there is no malware!
There are no viruses, which is a specific type of malware. A virus is a piece of software that can replicate itself and install onto a computer without any user intervention, corrupting existing code - much like a biological virus.
This does not exist for the mac (and barely exists for current windows versions, as their security is much better than it used to be). In Big Sur and later, the OS itself is mounted in a sealed volume so it cannot be modified when running..
All the malware that can affect your mac is of the social engineering variety: it requires YOU, the user, to be tricked into installing stuff. If you allow something to be installed, the "antivirus" software is not able to protect you from yourself, and it is not going to prevent from a nonexistent virus threat.
So any program that calls itself an "antivirus" is lying to you, and doing nothing but getting your money.
There is real cybersecurity, and there are scams that pass themselves off as cybersecurity.
MalwareBytes is a program by a respected security expert - note that it does not call itself "antivirus". So no, we are also not conflating cybersecurity with scams.
Your mac has a pretty **** good security built-in, and frequently updated. However, some users choose to turn that off, and instead install scams like "cleanmymac"... yes, this a well known scam, but people keep falling for it and giving them their money.
And when we ask the daily victims of this scam to run a simple diagnostic program, created by a respected member of this community, with the very purpose of helping people with their mac issues, they suddenly become suspicious... oh well.