Dear Simple,
You keep switching. You agree that yeshivishe clothing does not have any meaning before it is worn by yeshivaleit. Then it can not have an “inherent chashivus”. Then you switch right back to only an “expression of religiosity in wearing it”.
I disagree with that also. There is nothing being expressed by yeshivishe clothing. It just is that way. The fact that people perceive some symbolism in the black hat, does not change what it is. A dress hat. No more, no less.
To quote what I wrote above. #1880070 “I heard directly from one Rosh Yeshivah (He was as highly regarded as a yeshivshe daas torah as one can be.) that there is no reason to where a white shirt or a black hat. [Of course he expected his talmidim to wear them.]”