Why numbers alone do not define submarine power

Which navy has fielded the most powerful submarine force?

Probably the United States, even when Soviet or Russian forces had more boats, because capability matters more than raw numbers.

The United States probably fields the most powerful submarine force in history and did so at the time of the stream. That judgment is separate from a simple count of hulls, since Soviet and Russian fleets could be numerically larger. The American force could therefore rank as more powerful without being the largest collection of submarines. Capability, training, and the quality of the boats matter more here than raw hull count.