"20k images"
I assume based on the title, that the 20 thousand are the documents that are being managed?
If so, you need to figure out a way to manage them. You can build your own download service and store/update them on your own server, or use a blob/file system from azure or aws or another provider.
the uploaded images directory is mainly for things like application icons and maybe help videos. Stuff that a developer would manage.
If the users want to create/upload a file they would not be able to do that.