By definition, as a Genre, "Romance" has a happy ending. (If it doesn't then it's a Tragedy with a Romantic plotline, technically.)
I say this cause I have a theory that, generally speaking, people want to be happy.
We want to find meaning in our lives and relationships. Love is a powerful feeling with so many forms and manifestations that delight a human because it is among the most vibrant and wholesome sensations of bonding with another human being.
That's kind of the allure of Romance, and I think the reason why it's been a popular genre since humanity started telling each other stories. There is something Primal about it that can feel as stressful as life and death, while not literally being about life and death...sometimes lol. And people, me included, love that sort of social thrill. We are social beings, and quite nosy because we love to know interesting things about other people just for the sake of it. Generally. There are always exceptions like what one might find interesting xD
And as for why I think people will hook into a story at even the nearest hint of romance is cause our brains are powerful predicting machines. We LOVE trying to predict the future. (Think ships and conspiracy boards) We make plans and worry about outcomes of things all the time. So naturally, someone like me will hold out for any kind of romance just cause I love seeing love bloom. Also I think Romance is a place where subtext is easier to portray, while you really have to work in a different mindset for a more action or cerebral story.
I love action, thriller, horror and stories that don't have a drop of romance, not even a sub plot (which honestly gets me to pay more attention haha So you know where my real priorities are). But usually, usually they have to be particularly well done to keep my attention. Because they cannot reply on the potency of Romantic implications that our brains seem more than happy to generate on our own, Generally.
And its alright to be envious of the popularity of those creating in the romantic sphere. Heck I am too. But then it's important to note that you cannot control the audience and that since you too are a human being with interests, there will be others who enjoy what you enjoy as well. So a creators ONLY job is to create something they would honestly consume, and place it where people can find it for as long as it takes for people to notice.
If they don't notice on the scale at which you desire despite it being put out there, then that means the market has spoken and it may require going back to the drawing board and creating something new while improving one's skills.
