I wouldn't necessarilly call it a "luxury"
but rather a necessity,
Back in the DOS days when Viruses were proliferating all over the PC world
those in the security world used this example:
Sticking floppies from unknown systems into yer system,
is like not using a rubber and sharing / having multiple partners
They presented two options:
- buy an AV program
- abstain from sharing / using floppies of unknown origin
the major problem I see with most, if not all AV programs
is they still don't detect in browser Mal-activity
or if they claim they do, they don't do it very well
_