The reason you don't understand it is because whatever people say about you and your life choices, you have sexual agency. You are conscious of your sex drive and take responsibility for it. One of the major reasons sex declines among married women is they have an unconscious sexuality that is purely conditional and responsive based on the man. You see women on here deflect like this all the time, "well he has to have skills to get ME off!" OK, fine, no disagreement - but skills can be learned if you are patient and teach them. If he doesn't care to change that's one thing, but assuming good faith, "not being good in bed" in itself is only a problem when the other person doesn't know how to be good either. The whole trope about older women "having higher sex drives" is not true biologically. The only reason there is anecdotal evidence of it is because older women are more likely to self-confront at some point their own lack of sexual agency. They start deciding to fuck rather than just be fucked. But most women never learn to do this. Sex is something that happens to them, if someone makes it happen to them. And if someone doesn't do this (it gets harder every year), it eventually stops happening altogether. And they "don't care," because it was a source of shame they were always hiding from anyway.