Golf is a pass time for some, a sport for others and has been around in one form or another for hundreds of years. It is not a particularly complex sport on the surface, but there are underlying aspects of the sport that do complicate it. In essence, there is little golf equipment required to play - just a set of clubs, a handful of tees, and some golf balls. Golf clothing, while a huge market, doesn't really extend beyond the shoes and the gloves in terms of necessity.
Dozens of sporting goods name brands and high-end labels have their own line of golf clothing. In reality, golf clothing only has to be what the course requires. For instance, some courses may require patrons to be dressed in pants, not shorts, while others may have no dress code at all. Most country club courses will have a dress code, but members will already be well familiar with it. Public courses generally don't require any special golf clothing to play a round. Golf shoes have cleats and may or may not be required on a course. Gloves are simply convenient to improve grip.
However, because of golf's connotation that it is a sport of business rather than pleasure, it makes sense that many people scramble to have a closet full of quality golf clothing just as they would an expensive suit. Images of social status can certainly be made with expensive golf clothing, a nice set of clubs, and a half way decent game. A typical golf ensemble will consist of your standard golf pants, wrinkle free of course, a polo shirt that must always be worn tucked in and topped off with a belt. On a particularly sunny day, a hat may be necessary to help shade your eyes.
It is extremely unlikely that expensive golf clothing will improve your game, but it could very well improve your image on the course. If you are at a junior level of a company whose decisions are made on the golf course, and merely confirmed in meetings, then it may benefit your career but be cautious not to insult your boss. Some people take golf seriously enough that they'd rather play a good, honest game than to give a second thought to what anyone's wearing.