I would challenge your assertion that "any sufficiently complex application" will require lazily composed queries. I have worked on quite complex applications

I would challenge your assertion that "any sufficiently complex application" will require lazily composed queries. I have worked on quite complex applications that had no such need. Well encapsulated string construction in a Data Access Object pattern worked just fine. If you find yourself needing to lazily compose queries, then by all means, reach for a query builder. But I would encourage you to first examine whether you've split code into services that really should live together and whether that code should live closer to the data layer before you build a whole query builder. And don't reach for a query builder until you need it.