Well, not really, Monika can't reach it or see it as she can't do anything outside of her game/VM, but that doesn't mean that the reality of the player is more real, it's the same as the Metaverse has and they said that the VM's universe is as real their own. Monika also does things like having a twitter in their universe, so clearly she's not as fake and fictional as some image of a girl in a comicbook or something.
There's also the high possibility that I was wrong and Monika's universe is should be smaller than a real universe, as it is a
"small-scale simulated universe", "small-scale simulation" rather than medium or big, with "Small physical space", and a
miniature universe. Her universe being as real as the Metaverse's can just mean how everything is simulated and characters think things themselves rather than the size being the same. It does have space with stars in it but that is fitting for a "universe", otherwise they could just call it a city.