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.
I feel like most of the objections could be satisfied by having non-essential holodeck stuff in rooms only.
So you have a bed and lighting and core furnishings without it. But you get to use the holodeck to adjust all that to your taste, decorate the room, and othewise make the space yours. Maybe you get a virtual companion if you are lonely.
OTOH, I think replicators are already capable of doing most of what would be done by the in-room holodeck in that case.
To me the energy needs don’t really matter since energy consumption only matters in emergencies in Star Trek usually. If the first things you lose when there are power issues are your decorations and your virtual companion, I think that’s OK…