While I don't appreciate OP's abrasiveness, I'll share my 2 cents.
I think there are roughly two categories of porn games: games with a porn theme, or porn with barely any game mechanics.
The first category of games could stand on it's own. If you remove the porn, it's still a good game. And likely one that could reach a larger audience. So if you're in the business of selling your game, you wouldn't add a porn theme. Some games do flirt with it a little bit; I mean, I'm sure we all decided our party in Baldur's Gate 3 was to be a nudist party, right?
The second category is pretty much any VN or VN-adjacent game (life simulators, CYOA, etc.). These games can be extremely good as 'porn', but they're not much of a 'game'. In the sense that there are meaningful decisions to make, or puzzles to solve. The dialogue and visuals make it interesting.
I haven't seen a successful game that managed to make 'sex' it's central game mechanic. Some games try but it's either used sparingly or it becomes tedious really quickly. If you claim to have a silver bullet, I'd say go for it, maybe you know something that none of us do.
So I agree with that idea that porn games are not a genre, but a theme.
I come from a different time before VNs existed, they used to be called Dating Sims. You actually had stats in it, but you always utilized energy for everything even walking n talking. Often times energy & health were the same thing. They still sucked ass compared to Stick RPG.
We did have plenty of 3-pathway dodging SIDESCROLLERS not platformers, where you had to get injured to get the sex animations. Your platformers are way more advanced than what I had.
However those were in the minority back then.
We used to have slash & shoot to strip minigames with RPG mechanics.
And the other 90% were either quizzes or "click next for the animation after the progress bar loaded", often both.
No way did we have eroge wrestlers, brawlers & fighters back in the very early 2000s ... maybe 2008. Brawlers for some reason are a decent fit with hentai games, but I never saw idle games & autobattlers back then pair with hentai, neither RTS & Civilization type games. Wrestling games still seem like the best fit for a hentai game and I think some were made, I just don't remember the names, they would allow you to build your own wrestling moves and to do autobattle so you can relax and enjoy the match. Stealth would also have been good, but I never saw one.
Super Deepthroat still remains visually & mechanically the closest thing to making an eroge game, and it still doesn't even scratch the surface. It doesn't have stats/goals/grinding to make it like an arcade game with score & stuff like it's the 80s. Super Deepthroat mechanically is a good proof of concept to add to onto a bigger game like say Pokemon which also combined yet kept 2 different gameplay styles separated without sabotaging each other(for the most part). Pocket Monsters is still a poorman's Monster Rancher and Dragon Quest Monsters ... and Final Fantasy and Earthbound.
I would be adding salt on the wound if I said Custer's Revenge is more of a video game than most VNs today, but it would be true.
Albeit some would also argue simulators aren't video games cause they don't follow the arcade game format.