> You pay junior devs way way way more money for the privilege of them being bad.

Oh, it's worse than that. You do that, and they complain that they are underpaid and should earn much, much more. They also think they are great, it's just you, the old-timer, that "doesn't get it". You invest lots of time to work with them, train them, and teach them how to work with your codebase.

And then they quit because the company next door offered them slightly more money and the job was easier, too.