This is a flexible black box theatre stage:
They are one of the most common types of theatre, along with prosceniums, thrusts, and arenas. They are highly configurable, because all they are is a room painted black, and both the seating and set can be placed where ever one chooses.
Much black box theatre is performed with either minimalistic or no set, and minimal costuming. Everything from very traditional Shakespeare or Greek tragedy, to very modern experimental or absurd theatre can performed black box. The audience uses their imagination to fill in the blanks, and the show goes on.
The actors, meanwhile, get over themselves and do their damn jobs. They idea that you can’t act against a blue or green screen is patently false.
Even on a very built up and detailed set, there’s this thing called the Fourth Wall. It’s the one that the audience sees through into the action.
In a film or TV, this area is completely covered with cameras, crew, other actors, people’s girlfriends, craft services, runners with script changes…
In modern one camera filming, the cameras will often be directly in your face, over your shoulder, between your legs, kneeling in front of you shooting up your nose, or in a myriad of other very close positions.
There is never a moment in which you are not aware that you are acting.
Scrubs was filmed in an actual hospital, but even then, it was chockful of camera people and assistants and such.
You get over it and do it anyways.
The idea that “Oh, if only they’d had more real sets!” is garbage.
You can even act with something that isn’t there. There’s an entire movie where Jimmy Stewart’s co-star never makes an appearance. It’s widely regarded as a classic.
Acting is a learned skill that takes time and effort, and not some magical gift granted by the gods.