Ideas
Ok, I tested a bar in a small business venue, since it was the only thing I hadn’t tried. Bartenders and the bar always have the option to order food and drinks. They do produce the ordered food immediately, and mostly they mix and serve the drinks promptly as well. Sometimes though, the drink mixing would get hung up at some point and either drop off the task list or would just take forever to finish. This mostly seemed to happen when I ordered the drink and not the sim doing it autonomously.
I would say bars and bartenders (for me) are working on small businesses about as well as they ever have in game (maybe better), so the problem is just bars on other bar type community lots losing the bar functionality on anything other than the new small business lot types.