Instant-blindness lasers are really easy... but pretty much uncontrollable and unpredictable. They'd end up dazzling each other and knocking their own planes out of the sky.
Lasers that are actually lethal would be about ten thousand times worse, even handwaving the incredible technical challenges.
I remember Crime Pays But Botany Doesn't being a good channel. A person who got really into botany in jail, wandering around showcasing local flora and often discussing the social collapse and poor urban planning in evidence.