While OCPs is not considered as a risk factor

I have read that HRT is considered a risk factor for endometrial cancer but in the Menopause video, it is mentioned that the dose of ethinyl estradiol is 5 mcg in HRT for postmenopausal women and 10 mcg for perimenopausal women/young females which is even lower than very low - dose OCPs (dose of ethinyl estradiol - 20 mcg) while OCPs is not considered as a risk factor. Can you please clear my doubt?

Oestrogen-only HRT increases the risk of womb cancer. The longer this type of HRT is used, the bigger the risk. That’s why oestrogen-only HRT is usually only offered to those who have had their womb removed (a hysterectomy) as they have no risk of womb cancer to begin with. Combined HRT can reduce womb cancer risk. Thank you.