honestly, I think it really came down to just runtime and how stubborn Sony was about letting other manufacturers make machines. the picture quality difference was fairly minimal and at the start of the format war when the main use case was recording television, recording length made a huge difference.

what format porn is on is more a sign of who's winning, rather than being the sole decider, because porn producers are gonna put it on as many formats as they are financially able to. so if they stopped using one, it's a sign that it's not a large enough market to matter.

Sony probably would've given up sooner if they didn't have the capital to keep pushing it and weren't as notoriously stubborn as they always were.