These materials behave very differently:
Compostable plastic
Breaks down only in controlled industrial composting facilities with heat and oxygen. In landfills it usually behaves like conventional plastic because composting conditions are absent.
Oxo-degradable plastic
Fragments into smaller pieces through oxidation. It does not become food for microbes and can contribute to microplastic pollution. Many regions restrict or ban it.
Landfill-biodegradable plastic (bioWRAP®)
Designed specifically for anaerobic landfill environments. Microorganisms consume the material and convert it into water, gas and organic matter instead, leaving NO microplastics behind.
In short:
Compostable = compost facilities
Oxo = fragmentation, microplastics!
bioWRAP® = microbial digestion underground, no microplastic