It's a fairly mature market, and FWIW basic wood builds tend to wind up being too heavy to tow with a small car.
Camper, i.e. RV, popup, teardrop, etc.
The point that they are too light duty for this use I think still stands.
Basic possession is 25-50 a person, and if you want to have anything beyond an empty unfurnished trailer bed/batteries/activity gear/food/water is going to start to add up fast.
For me I could easily add 75lb of climbing gear, 50lb of snowboarding. Basic Solar panel is 20, batter another 15 and so on.
You aren't likely to be driving about with 2 people in the trailer.
For comparison, the smallest, lightest travel trailers you can buy come in around 1500-2000 pounds dry. And they are not rated for full-time living. Anything more durable will quickly weigh a lot more than a 1715 pound trailer can safely handle.