Going to mention the experience of a friend as I think it highlights a lot about the status of PIV sex.
Had a very intense friendship with a person who at the time identified as somewhere between a lesbian and a transgender f to m who was attracted to straight women and gay men, 15 years later he has now transitioned fully, is married, has a child (conceived via IVF using one of his eggs and donor sperm and carried to term by his partner).
At the time we were friends, he was very clear about his reasons for wanting to transition from female to male.
He had suffered abuse at the hands of an older male family member from a young age (around 5 or 6). There had been incestuous relationships between himself and other young family members who were also suffering from abuse whilst they were all still very much under age (he referred to that as being relationships that were comforting and helped him endure, then deal with/heal from the abuse to an extent).
The abuse came to light within the family when my friend had a nervous breakdown and suffered severe alcoholism and drug addiction whilst a tween/young teenager. it was hushed up and swept aside. The abuser paid for rehab and in the wider world/therapy and my friend was basically told to shut up and stop complaining, don't rock the boat. The abuser had a lot of power and influence, both within the family and beyond, quite a wealthy and connected man. Family position was that withdrawal of the abuser's "good graces" from my friend's nuclear family would be damaging to them all, so put up and shut up (his mum was the main proponent of this stance).
My friend staggered through their teenage years in and out of a drunken/drugged haze, AA and rehab, was sexually assaulted and raped again a lot of times by various people. Got clean when they moved away to university at the other end of the country (so away from family situation), started having sexual relationships with women, came out as a lesbian.
Later realised his wasn't attracted to lesbians, just bi and straight women and gay men who were interested in being penetrated not penetrating. Started to transition. Freely shared the fact that the only sex he was really interested/got a sexual charge from was very fast forced sex where he would penetrate another person with a penis, and that it did "look a lot like rape". Was prepared to perform other sex acts in order to maintain a relationship, but always as "the giver not the receiver". Ended a relationship with a girlfriend because she wouldn't let him penetrate her anally, even after 6 months of arguments and him helping her to get on the London property ladder.
He was very clear that he wanted to transition because men get a better life, that he didn't want to have to be the receptive partner, that a man/top got the better end of the "deal" in a male/female or male/male relationship, that sex for him was all about power and that it was more sexually exciting to humiliate someone verbally with no "sexual" contact than have sexual contact that wasn't his preferred variety (fast forced penetrative sex with no foreplay that looked non-consensual).
So, for him, transitioning was totally about being able to adopt a more powerful position in life generally, in relationships and in the bedroom. Sexual penetration was totally about being the one in control/having power. That to avoid unwanted penetration was to become a financially and socially powerful male person. That staying female and refusing to be penetrated was not a realistic or socially acceptable option. That giving social and financial protection/help creates an entitlement to penetration that cannot reasonably be denied.
(This is clearly not representative of male/female, female/female, male/male relations, or the motivations of transgender people. It was clearly born in early traumatic experiences, could in some ways be a way of dealing with that trauma.)