Burnout has been a topic for as long as I have been in the workplace (and I started before people had email or cell phones). With the pandemic, the conversation has continued.
The conversation has been so constant because we never really addressed the issue. Companies didn't want to address the issue. Burnout wasn't a good thing, but the alternative was to do less - get less done. That is the antithesis of every organization I know. Every org tries to do more and pushes the boundaries.
For a large part of my career, insane work ethic was a badge of honor. Work 70 hour week? You're a warrior. Need time off to rest and recharge, you are losing a step and have to worry about some other warrior taking your place.
Organizations that are serious about ending burnout and ensuring employee well-being have to realize that it means getting less done. That doesn't have to be a bad thing - it just means there has to be a heavier emphasis on doing the right things.