Exactly, signature antivirus only protects those who use it properly (most dont) AND luck out by not being among the first exposed to the new mutation of the day. Heuristic scans usually wind up with way too many false positives to be useful. These are just vain attempts to patch over an insecure core.
Securing the core would make everyone from marketing and a good portion of engineering extraordinarily unhappy by ruling out cool junk they would love to see and sell. You cant even sell that notion in linux land these days, and imagining it coming to windows is... well...
Only if Hollywood continues to pay handsomely for its development.
Yeah, running a browser which can directly impact your main system is the problem. Like tramping through back alleys and sewers looking for something while wearing your best shoes and suit. Better to have someone else do it or wear a full body condom. Or, rather, have someone else do it for you wearing a full body condom. Analogy: Run a windows VM and browse in the VM with the browser in a sandbox. Whether your main system is linux or windows it doesn't matter.