Towing laws vary by state but I think once you're over 1500 lb every state requires trailer brakes. They're not always electric brakes where you need the 7-pin plug and a brake controller. Surge brakes are common on boat trailers and rental trailers where there is a master cylinder connected to the hitch and when you apply the truck's brakes the trailer tongue pushes against the hitch and applies the trailer brakes.
I saw these A Liner campers a few weeks ago at the Pittsburgh RV Show. It's a pop-up but hard-sided, different levels of equipment, you can get a kitchen and A/C, and they don't weigh a lot.
https://aliner.com/