What I don't get about the need for fancy Lidar weed detection...

What I don't get about the need for fancy Lidar weed detection is that if we can already see the weeds sticking out above the wheat crop, why do we need lidar to tell us where they are? Farmers can already SEE where they are with their own God-given eyes. How expensive is it then, to just drive around with a small trailer behind a light tractor or quad, and just pull them out or do some local hand-spraying? Two people and an appropriate vehicle could cover a lot of wheat field in one day, for not very much wages and operating cost. How much labour does the lidar stuff need to save to justify its own development and equipment cost?

If driving a vehicle through the wheat field is going to destroy too much crop, send the farmer's labourer in on foot with a back-pack and a $99 drone, to locate and spray the affected areas.

But what would I know? I'm just a simple...

Pig.