Ok a few things to address first. All those “categories” you mentioned only being in straight porn and never in gay porn, you really need to revisit your favourite porn site and deviate from the hairless twink section for a minute. You will be surprised by what you will find.
As for watching straight porn, I enjoy it because I enjoy watching the men having sex. I like seeing the pleasure on his face, the ecstasy he’s feeling, and hearing his moans. I am as gay as they come and have zero interest in having sex with a woman myself, but I’ve gotten off many times to straight porn because I find the man attractive and I like seeing him get serviced.
With “queer baiting” becoming so mainstream these days, many straight guys who make amateur porn on onlyfans etc often make their content to target this audience, because they know that’s where the money is at. It’s become more common for the woman to be like a background character and the focus is on the man, with her back to the camera while she rides his dick and the man facing the camera, or she’s on her back and he’s on top with the camera behind him so you see glimpses of his hole.
It’s really not about the woman and all about the man. Some of my favourite porn scenes are straight ones. I suggest exploring a bit more and watching different types of content as it seems you might be stuck in a tunnel. You might find something you never thought you’d enjoy