This kind of interface only works when the number of choices is small. Suppose (in the case of your beer bot), instead of “Bud, Coors or Corona”, there were 200 beers available? Far too many for the bot to list for you. Asking for the particular artisanal beer you want might work — but if there are 10,000 different beers in the world, and only 200 available, the resulting “chat” would be like the MontyPython cheese shop sketch. You could say “Give me something hoppy, european with a nutty after-taste…but good luck with that! Does anyone really enjoy the interaction with a waiter when (s)he lists out all of the ‘specials’? In the end, it’s hard to beat a printed menu or a website with the space to lay out a two-dimensional list. “Browsing” isn’t something you can do with a very limited bandwidth and an essentially one-dimensional interface.

Perhaps chat apps have their place — but I think you’re over-selling things by claiming they’ll replace browsers and websites. Ordering beer in a stadium — yes, ordering beer in a well-stocked microbrew pub — no.