Modern red-dot optics on pistols and rifles have become reliable enough that some users omit backup iron sights. Enclosed housings, annual battery swaps, marked mounting screws, extensive round-count testing, and solar backup power support this choice.
If an optic fails, pistol shooters can still aim using the housing outline or treating the window as a large aperture. Rifle setups often skip irons because rail space is limited and some magnified optics physically block them. Gear quality plus dedicated training determine whether the approach is suitable.