It just popped up in my mind.
- You could decorate any room as you like. You don’t even need to step out of it most of the times.
- Other people can be projected inside it like Voyager’s doctor.
- Also rooms could be much smaller. They only need to be big enough a human(oid) can fit inside.
- In emergency cases most holograms can be shut off to match increased energy demands by weapons and shields. You only really need seating/bed and a (non-exploding) console screen.
- Much of the specialized rooms like a bar, med bay, etc. won’t be needed anymore as a holodeck can imitate all of them.
It irritated me a bit that a Discovery gets fancy floating warp nacelles but holodecks are… wait, does Discovery has a holodeck? I don’t remember seeing one.
They kinda did, they just didn’t go into detail. There were ships that were made entirely of holodeck at the new federation headquarters in discovery season 3ish, we just never got beyond being mentioned briefly and people going ‘Oh, thats cool’.