I think it is important to consider the reason that there is so much focus on species - it is the only rank that carries (or at least is intended to carry) some sort of real-world biological meaning. While there are many different definitions of species (due to differences in philosophy or differences in the underlying biology of the organism being considered), most definitions are intended to capture something “real”. For most organisms, this means trying to place the dividing line of species-level differences between groups that are not able to freely interbreed (with many caveats). All ranks above species are arbitrary. Speciation is a real-world process that can be studied, while there is no real-world process that leads to divisions between genera or kingdoms. Similarly, ranks below species are also somewhat fuzzy and arbitrary because they usually do not correspond to groups that can’t interbreed (otherwise they would be species, not subspecies).
The reason that dandelions are such a mess is that they have some very crazy biology that has led to this microspecies situation that really challenges our understanding of what a species is. The vast majority of species do not do what dandelions are doing. We are also stuck trying fit discrete categories onto a continuum - speciation is a process, and it is hard to know exactly where to draw the line and say that it it is “complete” or has gone at least far enough to call the two things different species. Dandelions seem to be going through the process of speciation, but we are caught with just a snapshot in time - it is unclear whether they will continue to evolve separately or whether they are ephemeral groups that will eventually collapse back together. Their method of reproduction makes it much more difficult to agree on species boundaries than it would be in most other plants.