I tend to think "stick to straight lines" was more pragmatic genius than a curse. Doable with tools available for surveying of the time, easy to communicate to staff and labour.
Modern Australian roads in the bush have inexplicable kinks, 100km of direct, then a bend. I think Fred on the tractor got bored.
See Also: https://en.wikipedia.org/wiki/Shudao https://www.newcivilengineer.com/archive/chinas-ancient-road...
Roman roads relied on thickness and rigidity, and sometimes needed excavations up to 2m deep. This meant they were long lasting but allowed nothing for temperature induced expansion or contraction. They were consequently prone to surface fissuring and uneven drainage.
The Chinese roads, on the other hand, were more akin to modern highways, being thinner and more elastic. They were built with a rubble sub-base onto which a layer of finely tamped gravel was added to produce a 'water- bound macadam'.