The problem is that is written by patients and there are a small subset of CFS who believe they are incurable.
I learnt from various CFS consultants that their patients convinced the condition is untreatable, who fear activity and exercise are much less likely to recover.
That fear of activity and exercise is based on very real experience - exhaustion and post exertional malaise can be very disabling and cause setbacks. It’s also hard to exercise when you don’t even have enough energy to get through work. However it doesn’t follow that no exercise at all is the way to go - that will simply weaken further.
I spoke to many people with LC and CFS. I also had the experience of managing a progressive AI illness where you have to exercise + physio just to keep going.
One woman I encountered had CFS so bad she had considered Dignitas. She started a programme of increasing activity in small increments - first she turned over in bed. Then walked 2 mins outside, then 3 mins. 5 mins might put her in bed for a week. She had to stick to her plan, and do no more or less the activity level for that day, even if she was feeling ok.
With exceptional discipline and determination she pulled herself out in 5 years.
In short: it’s a horrible illness, it’s like being buried alive: but it’s not terminal, degenerative or progressive. It can become incurable if you believe it is.