Fear and lack of awareness would be my guess.
This can be on the part of the clinician as well as the user.
There is a pervasive belief that women over 35 or 40 "shouldn't take the pill" which is not supported by either evidence or guidelines, plus the current social media evangelism about body identical hormones and disparaging of "synthetic" options, as well as a lack of knowledge about the non contraceptive benefits.
A lot of women who would really benefit from the bleed control and/or hormonal stability who are sterile or not sexually active with a male partner think the pill isn't for them because it is labelled as contraception, which is a real shame as they are potentially missing out on an effective treatment.
I also wish more people knew that the UKMEC criteria support COCP use up until the age of FIFTY, and even this only extends to contraceptive use, not therapeutic use ie to help manage a condition, which is an individual clinical decision thereafter.
A lot of people also STILL don't know that periods are completely optional and that it is safe to omit the withdrawal bleeds indefinitely, which I have done for the last 16 years minus a spell when I couldn't get my pill during COVID.
And I also think that instead of the disproportionate focus on a clinically minuscule increase in thrombotic risk and breast cancer, there should be more said about the significant ovarian cancer risk reduction evidenced with long term combined pill use, as well as reduction in endometrial and colorectal cancers.