Well, that's why I explicitly mentioned the drought pictures - LIDAR uncovers structures due to change in the terrain height once vegetation is 'removed', whereas drought pictures are grasses growing poorly on top of buried structures or their foundations. That's a very UK/European thing where a lot of the history has been covered up or ploughed over.

Just near me, a Roman road about 5km long was discovered last year by exactly this method. That's a non-trivial discovery. There was also a large Roman villa complex discovered the same way.

For LIDAR and structures, you're likely correct - there's vanishingly obvious structures left to discover that way.

https://www.bbc.co.uk/news/uk-wales-52911797

"Roman forts, roads, military camps and villas have been identified by a new analysis of aerial photographs taken in the 2018 heatwave across Wales.

Scorched crop marks uncovered about 200 ancient sites during the drought.

Experts say the Roman finds are key pieces in the jigsaw to understand how Wales was conquered and dominated 2,000 years ago.

Researcher Toby Driver said the discoveries "turn everything we know about the Romans on its head"."