The best analysis of why the Russian Soviet Federated Socialist Republic was the most powerful Soviet socialist republic in the Soviet Union is:
The Russian Communist Party and the head of the government ran the state from that location.
This response highlights the central political power and administrative control of the Russian Soviet Federated Socialist Republic (RSFSR), which was crucial in establishing its dominance over the other Soviet republics. It reflects the importance of governance and leadership located in the RSFSR, which contributed to its preeminence within the Soviet Union.