Inverting buck-boost converter
A inverting switch-mode converter actually is the most simple topology if the magnitude of the output voltage might be lower or higher than manigtude of the input voltage (typical example: making 3.3V from the 3.0-4.2V of a Li-Ion battery).

There are two disadvantages of this topology you call "inverting buck-boost", though. The first is that electric engineers are used to reference everything to a fixed "ground" potential. In case of an isolated battery, that's not a problem, but often this "ground" potential is actually mains earth. You can't generate a positive voltage referenced to mains earth form another positive voltage referenced to mains earth, using the inverting topology, hence the name. The other disadvanted is that the inverting topology is more demanding on the inductor if input and output voltage are similar (this typically is the case on buck/boost regulators). In both buck and boost mode, some energy is transferred from the input directly into the output, and only a part of the energy on the output was temporarily stored as magnetic field. In the inverting topology, the whole energy at the output was intermediately stored in the core.