Antivirus software is useful for most devices, but not all

You should definitely have antivirus software — or, even better, a complete security suite — on any Windows, macOS, Android or iOS-based device. However, this type of service is almost entirely pointless on FireOS or Linux equipment, as there are extremely few cyberthreats to consider. People who make malware want to target large numbers of people, and the comparably limited user base of FireOS and Linux devices means few to no cybercriminals will target these. But this might change in the future, so it’s best to stay up to date if you’re a user of either.