It's rather easy to produce qubits and place them in a box. The hard part is to make them interact with each other in a controlled fashion thus, adding one qubi

It's rather easy to produce qubits and place them in a box. The hard part is to make them interact with each other in a controlled fashion thus, adding one qubit to a large system is substantially harder than adding it to a small one. The only true benchmark is a factorisation of numbers. Number 21 has been factorised with nudging. Let's wait for a number 45 in the coming next decade.