For example the Anaconda is fucking huge. They have not rendered even 1% of the inside of that ship.
Yes, they have. When they design a new ship, they design and model the interior as well.
No, they haven't. There is no interior modeled or textured out. They made concept images, yes, but they never actually made the interior in the game engine. Star Citizen has more resources, more people, and a more capable FPS engine, despite all this, it has taken them months to block out each ship's interior and most of Star Citizen's ships are actually smaller than Elite's. You're absolutely bonkers if you think Frontier has managed to model those ships' interiors.
I guarantee it will be years before people are walking around their ships in Elite. In fact, I doubt it will ever happen at all.