Looks interesting but I have 3TB SSD or something close to it. How would this help me? I guess I'm trying to say space is not a problem for me. When I run out of space I move my documents to another drive. More specifically, my storage needs are modest and I organize everything into Downloads, Pictures, Videos, Code and all my space is usually taken up by one of those folders. Reducing the need for any kind of space analysis.
I can see this being useful for some people that want to re-organize how they use their disk space but you'd need to add some heuristics to the software to make it useful for such use cases. For example, if you group all images together and suggest to automatically move them to a single folder or a set of sub-folders in another folder I can see that being useful.