No you are the one arguing sementics.
You just said how the science behind thermodynamics says the Universe is a closed system but then you ignore the same science that says humans are open systems.
Now you are trying to say humans are the universe too cause they are part of it. THAT is arguing semantics.

Here let me refresh your mind

""II. Thermodynamic systems

Energy transfer is studied in three types of systems:

Open systems
Open systems can exchange both matter and energy with an outside system. They are portions of larger systems and in intimate contact with the larger system. Your body is an open system.

Closed systems
Closed systems exchange energy but not matter with an outside system. Though they are typically portions of larger systems, they are not in complete contact. The Earth is essentially a closed system; it obtains lots of energy from the Sun but the exchange of matter with the outside is almost zero.

Isolated systems
Isolated systems can exchange neither energy nor matter with an outside system. While they may be portions of larger systems, they do not communicate with the outside in any way. The physical universe is an isolated system; a closed thermos bottle is essentially an isolated system (though its insulation is not perfect)."
"