yea turns out lasers aren't magical lightsaber blades that immediately cut through anything, and actually need time to heat the surface of their target while having issues with penetrating thick or dense materials.
still less penetration less quick than if u used the nuke to propel a solid projectile real fast. photons have like negligible/arguably nonexistent mass, the real fun with lasers (as weapons) is using them to target enemy optics (mechanical or biological). one relatively weak but rapidly spinning laser array could permanently blind an entire unit or crowd of people nearly instantly if they don't have specialized protective equipment like high-quality mirror goggles (implausible) or camera/sensor helmets with replaceable/redundant sensors (likely doable in the future but impractical currently).