Agree 100%, wouldn't pull even a small trailer without them. Granted, if one was pulling a very small single axle with a 3/4-1 ton pickup perhaps it would be OK, but a small trailer almost always means a small tow vehicle, and in that case you'll want trailer brakes.
State laws require brakes on trailers weighing 2000-3000 lbs or more (varies by state). You aren't likely to find a 16-17 footer under that GVWR weight, so yes an RV trailer in that size range will have brakes. Either electric or surge, but most all will be electric. A pop-up that size might sneak by under the brake requirement, but even that is doubtful.
According to http://www.hitchemup.com/statetowinglaws.htm two states - Wisconsin and South Dakota require brakes on ALL trailers. New York requires brakes in trailers over 1,000 lbs. Three backwards states, including my domicile, do not require brakes. Massachusetts requires brakes on trailers over 10,000 lbs and Alaska over 5,000 lbs. All others are somewhere in between.
The laws of physics state it is ALWAYS a good plan to have trailer brakes! The laws of physics trumps all state and federal laws!