Because not having proper query language turns simple wishes into complex solutions.

But it does have way to query, if you of course only know SQL and didn't bother to learn the MongoDB way to query then for you, the uninformed outsider, it might seem complex. But so does ArangoDB or Neo4j or GraphQL.

Like, if you were never exposed to rxjs and are now trying to build things with it doing

  $stream.pipe(
    switchmap(),
    filter(),
    etc(),
  )

It does seem more complex than

  stream.map().filter().etc()

but it's only so because you haven't put in the effort to learn that way.

Sure, whatever.

Now write DBA scale ISO SQL 2016 / Transact SQL / PL/SQL in that interesting Mongo flavoured language, including database engine debugger integration, and JIT compilation.