We had BIOS based malware in the 90s too

Right. And what do you do when the filesystem comes back clean because the malware resides in some re-flashed firmware?

You can almost get a pass for being condescending ("try to keep up") if you know what you are talking about, but being both condescending AND wrong just makes you look foolish.

That doesn't help you if the code running outside your filesystem is compromised.

For example, a backdoor implanted in the disk firmware would be virtually undetectable for the vast majority of users.