Is a cup a cup if it has not held water? The cup possesses all means and physical attributes of holding water but has not. If the cup was suddenly used as a flower pot is it now a pot? What is the difference between using a cup as a pot and a pot as a cup?
The difference between the two is reason. Both objects were made for a reason, a task to complete. However, both the pot and cup possess no meaning. We often confuse this lack of reason for our existence with a lack of meaning in our lives. Often from a lack of reason, one falls into a constant quest to find a reason, a purpose, and a goal to fulfill. All of which will always fill oneself with emptiness after one achieves such goals. Either left with an ever-consuming hunger for more re-enforced by modern trends industriousness and "hustling". Or the pitfalls of depression, feeling devoid of use or what they understand as a meaning for themselves.
Both fall into the trap of Nihilism or essentially the thought that everything and everyone are totally and utterly meaningless. Furthermore, one falls into escapism letting oneself be defined by a reason or goal manifesting into their job, business, money, acquiring huge collections, writing on the internet on some weird web novel site, or even hobbies. The other falls into acceptance that there is no meaning and thus their life has no meaning.
No god, no universe, and no person can assign meaning to anyone. Meaning is a conscious decision that one makes with the self, it is completely up to the individual to decide their own life and how they want to spend such a rare fleeting moment on the blue speck.
However, that's scary, frightful, and anxiety-causing. Causing so many to fall into the trap of believing everything they do is meaningless. It's almost a comforting thought to believe that everything does not matter, it allows one to disconnect and not take the responsibility for one's own life, to be a passenger in the backseat of life.
In the end, life is only meaningless if you make it meaningless. You and only you can assign meaning to your life.