Sometimes it is not that the local agencies may not be able to do it...sometimes the problem is will the clients dare to take the risk or have the imagination to do it? Or have the budget to pull it off.
Our advertising budget is not that big. Plus, their marketing departments are conservative. They rather play it safe than to have their budget pull-off. This limits the creativity of the creative director.
I used to photograph commercial ads in the US. Most ads here are a far cry from those in the US or Europe.
TV Commercial can also be done on the cheap too. Look at some of the really cheesy ones during late night tv hehehe....
Sometime it depends on whether the relevant authority would allow you. You have to get permit and supply contruction plan work..etc to construct props to hang on buses, building or whatever.
How many saw the Mini Cooper Car Display that was hung sideway against a building face at Shentway near the MRT not too long back? I am sure to get that idea off the ground, various permits, approval from various authories, safety offices, rental to the building management had to be met plus fat creative fee for the concept and whatever also comes into play.