Adding media files to a project makes it’s exported file bigger.
But removing doesn’t make the exported file (zpp) smaller.
So the exported file only grows.
it would not be a problem if not this inserting error
You can use the command-line
zapworks tool to reduce the size of exported zpp files.
See https://docs.zap.works/universal-ar/zapworks-cli/ for documentation on how to download the tool, and then run it as
zapworks zppclean large_exported_project.zpp which will give a smaller
_cleaned.zpp file that will only contain the files that are required.
NB: This is only for reducing the size of zpp files; the published asset zips that users download to view your content are already the optimal size and will only contain the assets currently required by the project.
The best discussion of the details is in this thread: Clean your project before publishing! (note though that the title is incorrect as the user who started the thread didn’t realise the zpp size does not affect published size)