Why take notice? Because this entire division of life at one time rebuilt the earth's atmosphere by essentially poisoning it ... with oxygen. And as a nice lagniappe, cyanobacteria engaged in endosymbiosis with the eukaryotes we call plants and thereby enabled another atmosphere-altering process. You probably know it as photosynthesis.
Now that one big eukaryote is polluting the earth in its own way, cyanobacteria have responded in kind. As the only organisms that can reduce nitrogen and carbon in aerobic conditions, they must love what Homo sapiens sapiens is adding to the atmosphere and the earth's surface.