From the OP's link, repeated for convenience of reference
https://kffhealthnews.org/insurance/priced-out-obamacare-affordable-care-act-aca-premium-increases-peterson-kff/?utm_source=firefox-newtab-en-us
Insurers expect that with young and healthy people leaving the program rather than paying higher premiums, their remaining customers will be older, sicker, and therefore costlier on average.
Its likely that the people who dropped their coverage were also the healthier people, because sicker people were probably going to try to make it work however they could, to stretch their budget to keep their health insurance, said Cox, of KFF, a health information nonprofit that includes KFF Health News.
Just so people are aware of this death spiral dynamic. This has been much discussed as part of the reason for the large 2026 increases.
Another driver of higher premiums cited by several insurers is that claims submitted on behalf of patients have tended to be for more intense and costly levels of care than in the past. Such increased severity may be because patients are actually sicker, or it may reflect that hospitals or doctors are using artificial intelligence to find billing codes that can maximize their payments, the report noted.
With or without AI, this has long concerned me -- doctors upping the diagnosis and billing code to get a larger reimbursement. Doesn't that result in a person's medical record looking a lot worse than their true medical condition? I've seen a lot of discussion about the upcoding, but I haven't seen any of how it might result in a false impression of the person's condition that can mislead future providers into prescribing wrong treatments.