Compost isn’t something I’d even given much thought to, I got it in bags from B&Q and job done.
A long time ago I never bothered and used garden soil, perhaps an instinctive predilection towards natural farming – as exemplified in shumei.
At school I learned that soil has micro-orgnaisms that somehow worked symbiotically with the plants, but pretty much everything in the decades that passed seemed to run counter to that – perhaps my schoolbooks were from an earlier era.