Essentially just umami extract, making the food more savoury. Japenese use stuff like this in ramen as well. Dashis and tares use plenty of fish products (eg bonito flakes) and dried kelp (kombu) to make the dish more savoury. They aren’t used for their own flavour, but cooking with them enhances the other flavours.

Fish sauce in asian cuisine serves a similar purpose. It’s not used to add a fishy taste, but to give a dish more body. Afaik some Pho recipes use it despite not being a fish dish in any way. Essentially they function as natural flavour enhancers. Adding some MSG would serve a similar purpose.