I'll try to offer a balanced take on this, after having read both the Guardian essay and the research article you shared...
First, I think you are correct that if someone's running is a detriment to other important areas of their life, that's a problem. The research article you shared defined exercise addition (EA) as "a dysfunctional behaviour characterised by exaggerated training, loss of control over exercise behaviour, and negative life consequences that could be physical, psychological or social, or a combination of the three."
It's difficult, if not impossible, to reach a consensus on what would be considered "exaggerated training"; many people might consider 50 miles a week to be too much, let alone the 80-100 range you mentioned on page 1. But I think most of us can agree that the second two criteria in the definition - loss of control over exercise behavior and negative life consequences - are appropriate for determining the point at which training becomes unhealthy.
While I can't imagine someone ever training so much that they lose their job because they're repeatedly calling out sick due to being so exhausted from training, the Guardian essay is an interesting case study of someone whose overtraining resulted in a host of physical and psychological problems. The author cited missed periods, insomnia, acute and chronic injury, adrenal fatigue, chronic illness, deep exhaustion, mental illness, mania, and despair as issues she dealt with.
We know that even casual hobby joggers are likely to experience injuries, aches, and pains at some point, so I think a tricky thing with identifying the physical "negative life consequences" component of EA is determining which injuries are run of the mill, and which ones might be more serious indicators of EA. I think something like RED-S is an obvious sign that someone has taken it too far, but what about more common issues like tendinopathy, plantar fasciitis, and muscle strains? I don't think those injuries necessarily mean someone has EA or is at risk for it.
Given the pervasive nature of running injuries, I think it's crucial to examine the second component of EA: loss of control over exercise behavior. If someone simply can't control themselves, then that's a huge red flag.
If EA requires all three components of the definition listed above, particularly loss of control, then it's probably very rare. The authors of the research article were careful to point out that the prevalence rates they listed are likely to be higher than actual cases of EA because the estimates "stem from questionnaire data, which often may only reflect high commitment, dedication or passion associated with one's exercise." That said, even if only a small number of people actually have EA, it's worth being aware of it so those people can get the help they need.
I think where you went awry with this thread is framing it in such a way that put people on the defensive. In your very first post, you wrote, "That is why I can recognise the fact that some of the commenters on this board are also on the slippery slope, some just starting, others well on their way." Such a statement comes across as judgemental and inflammatory.
You also made some statements on the first page that aren't really consistent with the definition of EA and/or were huge assumptions about other people that could be totally off the mark. For example, you wrote, "Unlike some, I don't validate my worth as a person based on my ability to run a set distance in a certain time." Where did you get that perception from? I've been involved in running communities for nearly 30 years, and I've never met a runner I would characterize that way. Yes, most runners will appropriately feel proud when they run a PB, but I don't see that pride as the equivalent of validating their worth as a person. And I'm not sure what that even has to do with EA.
Additionally, you keep talking about running having an adverse effect on relationships. I've experienced and seen the opposite. My partner and I are both runners, and running is one of the activities that brings us together. We enjoy going on runs together, doing races together, and watching Diamond League and championship track meets together. We enjoyed going to Eugene for the 2022 world championships, and we just finished watching Sprint. We've met lots of couples in our running club who are similar.
I understand that not every avid runner is fortunate enough to be in a relationship with someone who shares that passion, but I wonder how often it becomes an issue. It seems to work out fine for ESP! Have you seen any instances where it's a problem? I haven't.
In conclusion, I think you've raised awareness of an important issue that affects a small percentage of runners but is an important issue nonetheless for those affected by it. It's a complicated issue to diagnose, so the awareness can be helpful. I just think you could have approached this thread in a different way that would have made people more receptive to what you wanted to share.