It's so easy to fall into a depressive spiral of "rest". TV binging, excessive sleeping, substance use. Low-energy, mind-numbing activities. But that won't help you recover.
This thought has been really helpful for me: "I used to think the cure for burn-out was lots of downtime and relaxation — and sometimes it is — but what’s worked better for me personally is regularly using my brain for something completely different. Otherwise you’re just wearing the same grooves into it all the time and (at least for me) that’s been where my worst burn-out has come from." [0]
I would encourage burned-out people, once they've had enough rest, to try working on something enjoyable and completely new (no computers?) and see if that work does anything good for their brain. You may not recover into 100% of the productive worker you used to be, but at least you can work again in a different capacity. And that might help you heal more fully in the long term. Remember that the brain can be rewired. [1]
[0] https://www.askamanager.org/2024/09/this-one-weird-trick-cur...
[1] https://www.psychologytoday.com/us/blog/radical-teaching/201...