I think all of it might be explained by this. At least to me it was always "common knowledge" that many athletes find a doctor willing to diagnose them with asthma so that they can get the medication.
That's not true at all.
WADA does not require a therapeutic usage order for normal usage salbutamol. Anyone who needs it can use it at the dosages required to control asthma.
At these dosages it has not been shown to improve performance, as mentioned in the abstract of the first link you cited.
Further I would offer [1],[2] and [3] as evidence for why you are wrong. Salbutamol does not improve performance at normal dosages.
1. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6135409/
2. https://thorax.bmj.com/content/56/9/675
3. https://www.wada-ama.org/sites/default/files/resources/files...
A test showed that they couldn’t get 12 trained cyclists to have a level above 510ng/ml in their urine, when they took salbutamol at the maximum WADA level of 600ug in an 8 hour period. [1]
The WADA threshold for salbutamol is 1,000ng/ml [2] So this level is about twice the level performance tested in your first link above.
Athletes can get TUEs for levels higher than the 1,000ng/ml limit or to take it using other methods than inhaling. [2]
Cyclists have been banned for having levels at 1,900ng/ml and 1,320ng/ml, and they were banned because the sport considers it a performance enhancing drug.
I imagine (but have no evidence, since they aren't published) that cyclists with a TUE regularly race with levels similar or above that. And without spending hours researching, I imagine this translates to other sports similarly.
[1] https://respiratory-research.biomedcentral.com/articles/10.1...
2) Maybe they don't use normal doses. As long as they get the prescription, they can take however much they want, right?
3) A few studies might not be enough to thoroughly prove that there's no effect under all possible circumstances. Again, as long as there is even a small amount of hope of it helping, many athletes are willing to try it.