Besides. Look at the simple COCKPIT size of an Apollo. That's huge. No where near a 100 of those can fit in an Elysium, and not only does an Elysium have to fit sub systems of all threads, but the turret as well as actual living quarters, corridors, a bridge, etc. I mean, let's get serious, the people aren't packed in there like sardines.
Why are you even comparing the Apollo with the Elysium? As I said, the Apollo is a
fighter, not a transport. The Elysium doesn't carry a large amount of guns, missiles, have shields, and have a powerful engine. It's a
transport ship, not a fighter.
Fighters do indeed require a lot of area for a big reactor due to the need for supplying several lasers. And secondary banks! It has to carry hundreds of Tempests! And a big engine, which can take a fighter to around 100 m/s on afterburners. The Elysium doesn't have that.
Engines for air/spacecraft are larger and more complex than a bus's engine.
Okay, fine. Take for an example, a Boeing 747; the fuselage is around 70 meters, and carries 366 individuals. The width is only 6 meters! The Elysium is 39 by 30 meters! (this gives you an idea that the Elysium doesn't carry 8 people at all!)
So, how the heck can a 747 carry
366 people? Wait, oh no, the F-22 Raptor carries only one pilot! Why is that?!
Because, it's a fighter. The 747 is a transport. The Apollo is a fighter. The Elysium is a transport.