Beat Saber: Why Custom Maps Cannot Be Made with Legal Music
medium.com
medium.com
https://github.com/idolize/saber-song-patcher
You just provide your own purchased or ripped copy of the song (pretty much all audio formats are supported) and it should just work™. The tool will verify the song is correct regardless of format/bitrate/etc using fingerprinting technology, apply any patches the mapper configured, and convert it to the proper format for Beat Saber.
Obviously this approach is not strictly "better" than the current 1-click system gamers have today, but at least there would be a viable alternative.