Chinese scientists claim to have discovered a new quantum submarine detection technology that's an order of magnitude more precise and can fit on small drones.
I imagine that's precisely the idea there. A sub is fairly limited in the amount of torpedoes it can carry, so a big enough swarm of drones becomes literally impossible to stop.
The US designed it's fleet based around one big heavy attacking another big heavy. It's in their nature to want a big threatening bully of a ship. It also helps that big heavy threatening things are magnitudes more expensive than smaller more effective things. The whole navy is this way. Its why we have so many carriers and why they get their shit pushed in in simulation after simulation by a force that instead uses a whole bunch of smaller ships.
Well actually also it's designed around one big heavy bullying a few smaller under equipped ships and or attacking smaller nations that aren't capable of defending themselves.