I'm really not sure where people got this idea that junior developers that are being mentored cannot contribute to the team. Are they going to contribute as mu

I'm really not sure where people got this idea that junior developers that are being mentored cannot contribute to the team. Are they going to contribute as much as a senior dev? No, but they can still contribute in significant ways. They can still fix bugs and find issues in your system, bring a fresh perspective on design and take ownership over smaller parts of the codebase. The reason why junior developers jump ship is because companies aren't willing to even promote people. So of course developers (of all levels!) are going to leave after 2-3 years when it's the best way to actually get paid and not taken advantage of by stupid CEOs that would rather have high turnover than a happy workforce.