On https://documentation.concretecms.org/9-x/developers/introduction/installing-concrete-cms, there needs to be an extra step after the cd hello-world step which states that the user should create the folder ./public/application/files. Without this, the next step will constantly fail with an error message that suggests it’s missing ./application/files.
Another solution could be including that folder in the composer build - maybe with a readme file in it if empty folders are not allowed.