And to add to this: Juniors are cheaper in salary, but that doesn't mean they're cheaper. Hiring is not free -- in fact by the sounds of it the OP has already

And to add to this: Juniors are cheaper in salary, but that doesn't mean they're cheaper. Hiring is not free -- in fact by the sounds of it the OP has already spend at least tens of hours unsuccessfully trying to hire someone. Mentoring time is not free. You're also paying them to learn (read docs, rework code, etc) whether you realize it or not. There's also a very non-zero chance you're incurring technical debt at a high rate, and that may not be apparent until you go to fix bugs (and cause 15 more every time you do) or add new features (and need to rebuild half the software to do so). Knowing how to build good, maintainable and supportable software comes with experience and this is what you're paying a senior for.