IMO, the author is writing from the perspective of Meson, a command line build tool used by individuals that takes arguments and caches them in a per-project file, whereas most of the negative replies are commenting from the perspective of sysadmins deploying software into homogeneous servers or Docker containers. Would make be a better program if MAKEFLAGS was not an environment variable? (IDK.) Would Git be a better program if the project directory was passed as an argument rather than as inherited state (the cwd)? (IDK.) Would less or nano be a better program if file paths were passed in as environment variables rather than arguments? (no.)