i’ve walked the via francigena and the italian section has quite a few sections of ancient roman road. they’re admittedly not contiguous, and are worn more extensively now, so i don’t get the same overall experience of treading on the stones for kilometers as they would have.
i target 35km/day with a 40L pack and finish my segments within 6-7 hours. asphalt, dirt and grass, and hiking trails (rocks, roots, dirt, etc) are the most standard surfaces and, to be honest, they’re all exhausting in their own rights so a change in surface is always welcome.
i can’t imagine marching most of this with near double body weight and then having to make camp.
I'd like to add they were also doing all that wearing leather sandals.
Imagine the Roman army with Adidas Ultraboost.
That's how they conquered all of their known world though, out of sheer bloody-mindedness.