If somebody's "burnt out" (for whatever definition of that you want to come up with), then sometimes it's just better for them to quit. It's not a great use of your time as a leader to be constantly discussing this.
If you've enacted change that allows motivated people to work where you work without "burn out" or you believe those changes are impossible to enact, what else is there for you to do?
If the root of the problem is that people are too wrapped up in the mission, look for people who don't care quite as much the next time you're hiring.
Or keep talking about burnout forever. That's an option, too.
If somebody's "burnt out" (for whatever definition of that you want to come up with), then sometimes it's just better for them to quit. It's not a great use of your time as a leader to be constantly discussing this.
If you've enacted change that allows motivated people to work where you work without "burn out" or you believe those changes are impossible to enact, what else is there for you to do?
If the root of the problem is that people are too wrapped up in the mission, look for people who don't care quite as much the next time you're hiring.
Or keep talking about burnout forever. That's an option, too.