Your Twitter thread shows the SQL that is equivalent, so it clearly can be done. Just because Malloy produces SQL that is impossible to read or write doesn't mean that the problem is only solvable with impossible-to-read SQL.
That would be like saying that Dreamweaver lets you do things that HTML+CSS don't because "look at how impossible to read the HTML output is!"
Give it a shot. Malloy writes the query in the twitter thread with a single database read. It computes the query, simultaneously at 4 levels of dimensionalization but only touches the disk once. No joins.
That would be like saying that Dreamweaver lets you do things that HTML+CSS don't because "look at how impossible to read the HTML output is!"