I hate writers.
This ship is perhaps the biggest “bulk carrier”. There are larger container ships, and there have been oil tankers that dwarf this ship.
I wouldn't say "dwarf". At 400,000 tons (the biggest of the Valemax fleet), would be quite a large ship. But, yes, the biggest oil tankers are larger.
Also, keep in mind, the ships are typically measured in dead weight tons. Meaning, with it fully loaded, which the 400,000 tons is the measurement of it loaded. And historically, some oil tankers have approached 600,000 dead weight tons when fully loaded.
However, the largest of the ships in the Valemax fleet at 400,000 dwt, is about (or will be) 200,000 tons. And the largest oil tankers, when empty, aren't significantly heavier, maybe 270,000 tons. At least not to a point where one would say it would dwarf the largest Valemax ships. The one described in this article is about 350,000 dwt.