So, as an example, I'm on Stelara. It's $10,000/shot.

Their patient assistance program will, without any consideration to income, pay up to $20,000/year of my copays/deductibles.

Why? Because the marginal cost to them of producing the shot is probably $10, so by paying (for example) someone's $4k deductible (or even $13k, if I'm a family on a Bronze plan) they make the remaining $36k that year off insurance. That person might picked a cheaper option or not have taken the shots at all if they'd had to pay the $4k out-of-pocket.

It feels awesome as a patient, but that's because I'm insulated from the enormous cost. Over time, though, it's pushing my premiums up, but in a way that's totally disconnected (from my perspective as the patient) to the pharma benefit I'm getting.