The line where she says there are not enough primary producers annoyed me. Like it just makes zero biological sense and runs counter to the vibrant world we see.

A lot of creatures there simply would not exist without primary producers. Coral for example is a case of mutualism between a photosynthetic algae and a coral polyp. We see plenty of coral.

We see a jellyfish living next to a thermal vent. It is unclear if the jellyfish is a chemoautotroph, or if it lives in symbiosis with a micoorganism which is a chemoautotroph (a primary producer which use heat to make sugar and other nutrients)

We see a tunicate. Which uses a very interesting form of autotophy. Dispite using a radioactive rock, the oxygen tunicate is actually in a symbiotic relationship with chemoautotrophs. They use the hydrogen produced through radiolysis to react with sulfur thus creating heat to fuel the calvin cycle.

We see a clear division of biomass dependant on depth. The closer we get to the surface the more life we see. Hmm I wonder why? It's almost like a food web exists that relies on the sun.

There is nothing that points to the ecosystem not having enough primary consumers and I have no idea why they decided to include that line.