Earlier quoted context omitted.
How does the pill being prescribed by a doctor help this? Do you think doctors are actually explaining this to patients? They are not. They don't have time. The PE firms who own them won't let them take the time.
I would expect someone to explain it; if not technically a doctor then a nurse or such, which is consistent with my experience of medical appointments.
The pharmacist can explain it. You can put it in huge text on the packaging. You can text or email people.
You could literally make someone DocuSign a single page PDF that just says "THIS ONLY WORKS CORRECTLY IF YOU TAKE IT AT THE SAME TIME EVERY DAY" in order to get their prescription.
All of these options get the exact same message across without being inconvenient and causing people to miss taking their birth control because they couldn't get a doctor's appointment, etc. There are costs to making people go into a medical office that you can't ignore here.