Something that’s missed in this analysis is that there have to be two elements in place for a promotion. As you’ve identified the person looking to move up need

Something that’s missed in this analysis is that there have to be two elements in place for a promotion. As you’ve identified the person looking to move up needs to be ready for it (I’m fully with you on it being BS to expect them to be doing the job already). On the other side there needs to be a position for them to move into - there isn’t an infinite number of Senior/Lead Developer jobs available in any given company, and typically the ones available are already filled. You’ll have a better chance at a large company where there are other teams you can transfer to, but then you’re dealing with the increased bureaucracy around that.