Ask HN: Can whitelisting executables replace anti-virus software?

Whitelisting, so basically maintaining a whitelist of allowed executables on a computer system and disallowing all other executables to execute - is this a viable way to replace bloated "antivirus" software that needs to run with root permissions and will kill your conpany with a bad update?

Are there any good reasons why whitelisting would not work / not be enough?

This is not trolling, I really would like to understand why that is not the default and instead we have "anti-virus" software everywhere.