What percentage of the road traffic do you think they constitute? How much of the value of the truck full of expensive seafood do you think the congestion charge represents? How many extra deliveries can a single driver make when they spend less time stuck in congestion?

Reducing the number of cars on the road helps everyone: we tend to focus on the enormous quality of life and health benefits to residents but it also helps everyone who doesn’t have the option of not driving, too. Ambulances getting stuck in congestion less is a win. Deliveries which can’t be done using cargo bikes similarly benefit from reducing the single greatest source of delay: cars.

They're probably enjoying the reduced traffic their trucks have to deal with?

The truck carrying $10k in sushi can afford and justify the daily $9 fee.

Can they not afford to pay $9 per truck per day? Seems like a bad business plan that can't manage to pay such a minor fee. That's the design of the congestion charge it disincentivizes optional trips but is small enough for any money making business to absorb.

With reduced congestion, delivery companies will find marginally increased productivity (maybe 1 more delivery stop is possible per shift, for instance) that will likely make the fee worth it