How do frogs fit in the world? What impact do frogs have on the environment or other organisms?

This question seems to be asking about the ecological niche of frogs. An ecological niche, in simplistic phrasing, is essentially the “job” or “role” that a species performs within nature. It includes the interactions of a species with other members of a community. This could include things like competition, predation, parasitism, commensalism, and mutualism. Additionally, there are a variety of abiotic (non-living) factors that affect the particular niche that a species occupies; therefore, there is not a single, simple answer to this question. The reason for that is because there are nearly 5,000 species of frogs worldwide. With that many species, it is nearly impossible for all of them to have the same ecological niche; however, some very broad generalizations can be made about frogs and their role in nature. Frogs are a predator species that feed on insects and small animals like earthworms, minnows, and spiders. Additionally, frogs are the prey of other predators. As such, ecologists consider frogs an "indicator species" because the frogs are a good indicator of the health of an ecosystem. If the frog population blooms, then population levels of what the frogs feed on begin to decline; however, this is only temporary. As frog populations rise, there is more food for the higher level predators that eat the frogs. Those populations will then increase, and the frog populations will begin to decline as a result. With the decline of the frog populations, the lower level species will rebound in population because there are fewer frogs eating them. This is why nature is never truly in "balance." It's constantly readjusting as populations of individuals species rise and fall within communities and ecosystems.
https://defenders.org/wildlife/amphibians

https://www.britannica.com/science/niche-ecology