> You don't need to repeat anything for software. Software can be copied arbitrarily for no practical cost.

...Or so think devs.

People responsible for operating software, as well as people responsible for maintaining it, may have different opinions.

Bugs must be fixed, underlying software/hardware changes and vulnerabilities get discovered, and so versions must be bumped. The surrounding ecosystem changes, and so, even if your particular stack doesn't require new features, it must be adapted (a simple example: your react front breaks because the nginx proxy changed is subdirectory).