Using wicker as a carriage building material was popular because it was lightweight, easy to come by, fairly sturdy for using as containment in sidewalls, trim. Back then labor was cheap to weave and put it on.
There are a number of VERY OLD sleighs that are wicker bodies. The undercarriage with runners was wood, but all the sides and dash, were wicker. I would say fairly well used, and mostly in fair shape for being 200 years old. The folks at home made them, could easily repair them with reed from the swamp or bushes growing locally. I know my wicker laundry baskets last well. Good for years, even with heavy loads, rough use at times. No paint or finish on them. Not an expensive model either.
Wicker was popular as “country” because it required no painting, didn’t show the dirt, and vehicle standards were different than city driving called for. You were supposed to look more casual when out in the country, at your summer home/farm, out “rusticating” with the locals. Not polite to be obviously showy in the local company.
The wicker Ladies Phaetons are pretty, and fairly numerous because you see a number of them out being shown. Made by various makers, all pretty. Name makers like Brewster offered wicker in vehicles, still to be seen today at CAA funtions or private collections.
Funny how some old reeds can be shaped into many elegant and useful items, still sturdy and useful over time. Would not have come to my mind as a carriage material, until I saw them in use.
Governess carts were usually driven at a very slow pace, with small animals pulling them. That would allow governess or child “keeper” to keep their eye on the small people. I understood that the governess was expected to sit in a back corner near the door preventing escapes. She could then observe all in vehicle, be able to watch children and pony by just looking forward. Slow speed was less effort to drive with distractions of children. Perhaps bacj corner also was less body twist than sitting in a front corner. I have seen photos of Governess cart pony being led by a groom, not really driven by children inside.
I think old time folks were just more stoic, about bad body position and pain. Sidesaddle riders always have a twist in the spine for the “elegant” look on their horse despite both feet on one side of animal. Part of the flowing look of correct rider with skirt or apron. Staying correct in your equitation is NOT easy on a sidesaddle. I KNOW a few hours out riding that way just KILLS YOUR BACK!! Sitting for hours in chairs with no spine touching the chair back, was trained into children of the upper classes. Posture said a lot about a person, especially ladies in corsets who could not bend anyway.