Probably would have to be a passion project. I don't think there's a large enough market for it. Maybe someone should contact the Apple UI team to import these old themes?
Why do you think computer users today would be so much less interested in customizing their desktop that there would be no market for it? I think if a tool/app were to appear that customized the modern macOS finder to this extent, it would be #1 on the AppStore within hours