Alright, I'm intrigued. What use case isn't filled by most nightclubs?

-Bouncers often compulsively search you in order to make sure you don't bring extra alcohol inside

-Prices are at a ridiculous premium, typically to profit from the artificial scarcity but also in order to discourage and punish drunken behavior

-Loud party music galore

What exactly is missing?

"but also in order to discourage and punish drunken behavior"

No club is trying to discourage patrons to have drinks.

Also, some people like conversation. You can't have that at a nightclub

Depends where you live. Many clubs display prohibitive/punitive fares on purpose, by the owners' own admission - not everyone is a rational market agent.

In many clubs there are also areas (usually smoking ones, but also backrooms, lounge areas, and so on) where the sound is muted and conversations (and other things) easily take place.