These days, to be "complete" wouldn't I need to know frontend JavaScript, neural networks, and a dozen other things I don't know? What does "complete" mean?
Well by definition 'complete' means to "the greatest extent or degree". So a complete SWE would need systems knowledge. But is anyone really a complete SWE? Even people that are experts in systems probably aren't complete because they don't know AI.
So we aim for well-rounded. That's the best we can maintain.