Likely spec’d by the accountants and managers who’ve never ever been close to an artic truck / wagon / lorry but listened to all the “this will save CO/2” marketing crap.
Suspect if they become more popular - the damage costs and extra cost of trailers will make them quietly disappear. Double deckers are a much better idea and they can be a royal pain.
Don’t actually understand why they cant put all the wheels further back rather than one set way behind which has to messup the pivot point.