In most religions, there is an understood and agreed-upon attire, a uniform you might say, that is expected of its clergy, ministers, priest, rabbi, monks, etc. And, with that arises in fashion, a dress that instills the concept of poise, stature, wisdom, respect and most profoundly, enlightenment. In the days of the birth of Judaism, Christianity, Islam, Budhism, etc, communications and trade were limited to finite geographical regions. Thus, one finds that the clerical attire tended t0 be reflective of the period's or cultural fashion sense. Hence, the long flowing robes, turbans, etc.
Scientology being a modern religion follows the same fashion sense of moderneity. With the miracles of modern technology, our society is no longer limited to one geographical region and thus fashion of the 21st Century tends to be a global fashion sense. The underlying thread of acceptable and respectable dress today is the now "classic" business suit and thus, we see many of the Scientology Churches, now located in every continent, being manned by staff dressed sharply in business suits. As fashion evolves, we see the enlightened and well-respected step up also in the evolution.