Biden gives his speeches from a fake White House TV set

Why has Biden ordered to construct a fake White House background set, for his speeches? No other American president ever did such thing! When presidents address the country, they sit in the White House, nowhere else. If Biden really is in the White House, why would he need to build a fake White House background, for his public appearances? The official explanation is that he needs a teleprompter to read his scripts, that others write for him. But this can also be done in the actual White House. There is no need whatsoever to build a set outside of the White House for this.

And why are all present reporters strictly ordered not to mention the fact that they are never in the White House, but in a TV studio, that fakes the White House? If this is noting fishy, why hiding it from the public?