The mate who hit one in a yacht while mid Pacific begs to differ.

I wonder how many other hazards are out there. I have feeling it's small fraction compared to something like tree logs or g*d knows what else.

He has also hit a whale. He has had a lot of alarming things happen while out sailing. I learned to avoid going out with him.

FWIW there were some bizarre orca attacks around Portugal or Spain recently.

Imagine running into a quarter mile long string of telephone poles washed away 5 years ago in a hurricane...

Robert Redford in “All is Lost”.

There are quite obviously consequences, but perhaps not for the people who are in a position to ensure the containers don't fall overboard? Somebody is certainly losing money here.

Insurance

So insurance companies are losing money and raising premiums accordingly?

Perhaps nobody is losing enough money to really care about the problem. The graph in the linked article suggests that 11 out of the last 13 years, losses have amounted to around $80 million or less. A lot of money, but perhaps not a lot of money to the shipping industry and/or their insurers?

Considering there are individual ships that carry more than a billion dollars worth of cargo and way more containers in a single trip than are lost in total in a year, I think you are probably correct.

It amounts to a rounding error when you look at yearly cost of shilling. Remember the Suez Canal when blocked was costing 400 million a day.

Yes it's priced and amortized all over the system.