Fixed cost to create, sure. Not fixed cost to keep up to date, running on the current version of OS, hardware. The basic design of a simple wheelbarrow has not needed to change since its invention. A wheelbarrow made 30 years ago will still work just fine. Almost no software written 30 years ago will still work on modern systems without someone doing additional work to support it. And for the few that do, no one wants to run the 1990s version. They want to run the 2020s version.