I'll clarify, there are people who've recovered completely 100% and others who've recovered 80-90%, I've read about both. Others on this forum should chime in here to back me up because I'm sure they know or have read about people who have recovered.
In my family we have had 3 clearly defined, diagnosed by an ME/CFS specialist, cases of ME/CFS. While our symptoms and treatments were generally similar -- flu-like, with herpesviruses, no GI problems -- our paths to recovery (or not) have been different.
1) My uncle, in his late 60s-early 70's during treatment, had what I would call a mild case of ME/CFS. It sounds like yours,
leokitten. He could continue to work, but could do nothing else. He was about a 7 or 8 out of 10 on most ME/CFS scales. After many years on antivirals, which changed as new ones become available, he now appears to be fully recovered, although now retired. He takes no meds to treat symptoms and is a very active late 70 yo.
2) My daughter, 12 yo at the time of our common infection, but had mild symptoms and was in and out of (apparent) remission until at 17yo she crashed into continuous illness. By the time she got antivirals, she had been continuously ill for 1 year and was within a gnat's eyebrow of having to drop out of engineering college.
She managed to stay in college by living at home, napping long hours (including in her car between classes), and doing nothing else -- no social activities, no other work or research other than classes. I would call her mild/moderate -- moderate at her worst. She could not have continued to "work" as a college student without the tons of daily functioning support she got, mostly from her dad. She was rated a 5 or 6 out of 10 on an ME/CFS functionality scale. She was not house- or bedbound, even at her worst, but definitely impaired and very sick.
Almost 2 years on Valcyte gave her a huge improvement in her condition. She finished college (and got into graduate school), lived in an apartment on campus, and had a satisfying social life. She has traveled quite a bit and is physically active to the point of taking multiple week-long dayhiking trips. She does not appear to have PEM.
Is she recovered? I'd say no. She's fully functional, not obviously limited by her illness. She still has to take prophylactic antivirals because her immune system does not keep herpesviruses suppressed. She also needs treatment for sleep, hypothyroid, and low blood volume. She still has immune abnormalities.
3) I got sick at the same time as my daughter with the same flu-like illness. I have not been well since. I flailed around (not being a medical research person) trying to find a doctor willing to help. For 4 years I didn't even find a doctor who believed me, much less one knowledgeable enough to diagnose or treat me.
By the time I got antivirals, I had been sick for 6 years. I was bedbound at that point. My cognitive symptoms were so bad that I couldn't read. I couldn't remain upright for more than an hour or two. I had flu-like symptoms constantly. I was about a 3 out of 10 in terms of functionality.
I got antivirals at the same time as my daughter. While I improved tremendously on them -- from bedbound, to housebound, to working an easy part-time job for a sympathetic employer tutoring math and science for her kids -- I am far from recovered. Although I get around in my house just fine now, I still need a wheelchair for longer (100+ yards) movement or I get PEM. I have multiple immune abnormalities and take symptomatic treatments for sleep, hypothyroid, low blood volume, and more.
I no longer expect to return to work as a research engineer or college professor. I'm glad (but not satisfied) to not be bedbound and incapable of caring for myself and to be working, even part-time at a job far below my qualifications.
We are generally considered to be "success" stories in ME/CFS. Treatment has tremendously improved quality of life for all of us, but altogether I would not consider us "recovered".
My uncle, who had the best outcome, was never very sick to begin with -- by ME/CFS standards, that is. I suspect that was one reason for his success with treatment.
My daughter was young and only a year into being continuously ill when she started antivirals. She was only moderately ill (by ME/CFS standards). I attribute her return to full functionality to her youth and relatively quick aggressive treatment. Full functionality is NOT recovery, however.
Me, I was sick longer, and was more severely ill. I hope for more improvement, but I no longer expect a return to full functionality. I suspect that recovery is not possible for those of us who were severely ill and/or ill for more than 5 years or so.
I don't believe that substantial numbers of PWME have recovered to 80-100% of their pre-illness condition. I haven't seen any evidence supporting that theory. All I have to do is look around PR, or talk to the several specialists I've seen to find plenty of people who have NOT recovered.
The "recovery" cases I have heard about were either people who were mildly affected (as in still able to work), or young and got aggressive treatment very early. Dr Bell discovered that many of his patients who were thought to be recovered were still impaired, but had adjusted their lifestyles to accommodate those impairments. While no doubt those people were quite functional compared to many PWME, it is not at all clear that they were near 100%.
My personal theory is that if PWME are treated early and aggressively with antivirals, abx and immune modulators, many would achieve something approaching full functionality. But that's my personal theory with minimal scientific evidence to support it -- yet. The tragic reality is that the VAST majority of us do not get treated early or aggressively and end up permanently impaired to greater and lesser degrees.