Do I need antivirus software on a MacBook Air?

Regarding the MacBook Air: No, not really — at least not a paid, always-on one. macOS is already locked down with System Integrity Protection, app sandboxing, and Gatekeeper. The real risk is you clicking a sketchy link, and antivirus won’t fix bad judgment. If you want peace of mind without bloat, use the free version of Malwarebytes for manual scans only. Save your money — common sense is the best antivirus.