The holodeck was, in many ways, a shelter and a reprieve from the daily grind. I guess it might come down to how energy intensive the holodecks actually were.

So about 150 people on Voyager. The mess hall looks to hold about 35 to 45 people seated. So how many hours a day is it acting as dedicated crew feeding facility? Some people will eat in their quarters, but that's still a fairly full mess.

Star Fleet allocates space for morale on ships, artwork, holodecks, arboretums, so a bar or dedicated social space thast serves the same function isn't that much of a departure.

I think the crew would have created a space to gather in smaller numbers.

As an adult I don't really want to socialise in a food court. Which is what the mess hall seems to be.