I think on average beaver ponds promote more biodiversity than human farms, allowing for a larger number of specialized species to find homes. This article gives a breif view of how beavers help to boost biodiversity, including hosting beaver pond specialists. Some methods of farming promote biodiversity, but monoculture largely prevails - 80% of arable land plots are used for monoculture globally.
So we need to do better and strive to do as good of a job as the beavers do.
I can definitely see how a race of superintelligent industrialized beavers could be a bad thing for the world, so as far as the comic goes you are right lol.
As for real life beavers - whether beavers are conscious of it or not, the way they relate to the ecosystems they inhabit in some ways sets an example for humans to follow. We don’t need to limit ourselves to only living in North America and Scandinavia/Eastern Europe, but maybe we should try to farm in ways that intentionally promote species diversity. There could be other lessons to take as well, such as spending more effort farming appropriate locations (beavers spend considerable effort finding the right place to set up shop) - many farms around the world are located without much thought toward how they will relate to neighboring ecosystems.