Most use fast assembly using wood screws rather than nut/bolt fittings. This means that it won't take too much force to have the screws tear out. The video demonstrates the end result.
They also use glue ...
Bad news , most of your modern airliners are glued together ..
Good news , modern glues can be stronger than welds - If you use the good stuff .
So yeah , manufacturing has changed greatly because of technology .
But any caravan , any vintage , will not take crashing well .
30 Years ago + a little more , I saw the result of two caravans coming into contact on a narrow bridge ..
Both caravans exploded , there was stuff everywhere for a couple of hundred square meters ..
Both cars were towing chassis , nothing of the caravans remained on either chassis . I mean nothing . ( Bare to the bone )
Caravans are not built to crash test standards , your supposedly meant to be very careful when towing a caravan .. And that weight thing ...
A lot of people don't understand the weight thing when it comes to towing ...