One of the things you realize after you get some experience as a manager is that not everyone is equal, so not everyone needs to be treated equally. It's a tech company, not the drive thru line at McDonalds.

People leave for a lot of reasons, and not having opportunities to grow is one of them.

You want to be equal? Everyone with the title Senior Staff Engineer gets to work on super awesome forward looking new space car. Or maybe just 20% time and a ton more stock options.