Clothes also serve as a second barrier to our body. To protect it from unfavourable conditions and harm.

Example:
Preventing insects from crawling on your skin.

Less risk to get bacterial infection. Imagine if your penis is dangling around in the open and it touch something infested with bacteria. Gotta amputate la like that...

Also I don't think you want to be in a crowded train where your p**** is touching an old lady's buttocks do you? Maybe the old lady will enjoy it la..LOL

Anyway, I think it's more practical. Like I say, hygiene. Imagine if you sat on the chair in the train where the previous person who sat has ringworms, tapeworms, etc. Crawl up you a-hole.

The symbolic meaning comes with the types of clothes. E.g. King's clothes, jester's clothes, peasant's clothes, priest's clothes. They used clothes to identify the occupation and social standing.