You can outgun by far your opponents, and yet they can find cheap and effective ways to make you bleed in ways you cannot sustain for long.
This was already visible in Ukraine, where minor investments on Ukrainian side (like sabotaging gas pipelines, oil refineries or production plants) can lead to magnitude of orders outsized impacts on the war economy (and economy in general) for years.
Now Iran's showing how gargantuan has to be the US' and Israeli effort to prevent a major and long lasting choke on world economy that can be threatened by few dudes with a handful of drones/divers or small boats.