Running Windows software on a Mac costs more disk than you think

Running a Windows program on a Mac means building an environment for it, and the tools that do this build a fairly complete one each time. The disk cost is not the program, it is the several hundred megabytes of scaffolding around each one.

Where each tool keeps things

du -sh ~/Library/Application\ Support/com.isaacmarovitz.Whisky \
  ~/Library/Application\ Support/CrossOver \
  ~/.wine ~/Library/Containers/*Whisky* 2>/dev/null | sort -h

One bottle per app is a choice, not a requirement

Separate environments per application is the safe default, because one program's requirements cannot break another's. It is also the expensive one. If you run several well behaved applications, putting them in a shared bottle costs a fraction of the space, at the risk that one installation affects another.

Removing them properly

Delete bottles through the tool's own interface rather than removing folders, so its list stays accurate. Removing the application itself does not remove the bottles it created, which is the usual reason a Mac still holds several gigabytes for software that is no longer installed.

ls ~/Library/Application\ Support/*/Bottles 2>/dev/null

Runtime versions accumulate

These tools download their own runtime, and upgrading fetches a new version without removing the old one, in the same way that Playwright keeps a browser per build. Check for a versions folder inside the tool's support directory and remove the ones nothing points at.

Compared with the alternatives

A full virtual machine costs far more, is far more capable, and behaves the way virtual machine disks behave, which is to say it grows and does not shrink. A compatibility layer is the cheaper option on disk as well as in memory, and both are worth reviewing when the software they were installed for is no longer used.