Why do DC/DC switching controllers seem to favour the buck-boost topology over similar ones like Cuk, SEPIC and Zeta?
I am looking at various DC/DC converter topologies for a power system I am designing. The most suitable topology for me is one that can perform both step-up and step-down functions, so I am looking into buck-boost and similar topologies like Cuk, SEPIC and Zeta.
While selecting the candidate ICs for the switching controller, I noticed a curios thing. On Digikey, where it is possible to filter by topology, the buck-boost & four-switch buck-boost topology occupies a large majority of the market. For instance, Digikey's catalog lists 471 active switching controller designs for a buck-boost topology, whereas for Cuk/SEPIC topologies there are only a handful of chips available (in the range of 15-20 chips).
Why is there such a preference for buck-boost topologies over Cuk and Sepic? Or is this just a shortcoming of Digikey's catalog?