I’m sorry, but this is just a wrong assumption on your part. The point about having the …/Artist/Album structure is that it is the easiest for Roon in recognising what you have in your collection during the import process.
Once that is done, then object entries corresponding to Albums, Composers, Releases, Artists, Compositions and more are created in the Roon database. You can browse the object graph in many different ways, not just by Artist or Album, and you can use the Focus tool to slice and dice your collection along many dimensions to create smart playlists.
I’ve said it before, having a folder structure of …/Album/Artist is the best way to oil the import process of Roon to ensure that everything gets ingested quickly and as fault-free as possible. The old joke about “what’s the best way to get to Tipperary?” applies here.