I love your comment the house!
(づ￣ ³￣)づ
But then again some people can do both! Like in this webtoon - Dark heaven.
Link - http://www.mangago.me/read-manga/dark_heaven/t's a masterpiece btw
Of course there are those who can but you can't force someone to do both if they can't. I see a lot of comments, on other stories, criticising a character when they refuse to try bottoming. IRL, you really can't force someone, especially if they have already tried it and found they can't. There several manga that I have read featuring seke couple but such manga are rare.
This manga actually shows how healthy their relationship is, and even though I was disappointed it was not a switch, I'm still glad they tried, but you were right that not everyone feels pressure from both, though it most will feel pressure and yet most yaoi are stuck in the heteronormative role of uke and seme.
On the topping issue, both have tried and found that one can bottom and one can't. I watched a video from Rich Lux and another perso they, forgot their name, said some people can't do both, topping and bottoming. But it is important to at least try both before concluding you can't do one. And this story did! I love re-reading this.