TBH I think most journalists from these publications are more qualified to write about posture health benefits than they are qualified to do actual journalism.
†https://en.wikipedia.org/wiki/Mysore_style https://en.wikipedia.org/wiki/Ashtanga_vinyasa_yoga https://www.youtube.com/watch?v=aUgtMaAZzW0
There isn't? From what I understand slouching means the muscles are not supporting the joints as they are supposed too leading to increased wear and people who slouch tend to let chair backs support them which leads to decreased muscle mass exacerbating the problem. Makes sense to me but I am not a doctor. Personally I just find slouching to be uncomfortable.
Also, if you've ever had back pain at a desk job then you probably know the value of lumbar support. Sitting hunched over or fully reclined is just not a feasible way to sit for 5-7 hours a day, 5 days a week.