I think you will get a variety of responses here op as relationships vary so much and are a law unto themselves, but generally, if you listen to various podcasts there seem to be quite a few young people in sexless relationships too, as well in as the long married and coupled up.
Whether this is down to contraceptive pill hormones in the water supply, increased porn use , or poor nutrition, women who are stressed out by working ft AND carrying the majority of the domestic and parenting load, a general lethargy that has descended post-Covid, I don’t know, but I do think that an additional cause is that so many men fail to understand the basics of sex.
The following are generalisations of course but:
~the fact that most women take on average 15 to 20 minutes to warm up to it properly, rather than a man’s much quicker sexual response.
~ The fact that there isn’t proper sex education in the uk.
~ The fact that so many men don’t wait for a woman to orgasm first.
~ The fact that sex is depicted in so many male directed films and porn as primarily involving piv orgasm when it simply doesn’t happen that often for very many women.
~ The fact that women respond mentally as well as physically and often need to feel safe and be in a good communicative relationship to fully enjoy sex (not always of course but communication is key)
There is such terrible ignorance surrounding these basic facts in the male population, and women are so conditioned to go along with these prevailing masculine myths and worship of the penis etc, that I think sex for many women becomes a chore not a pleasure.