Romance is the bane of human existence
jk but it's one of the most relatable experiences humans understand. And drama-wise, the juiciest drama seems to revolve around relationships in real life, games, or comics.
For me, I care more about the purpose of the story. Romance is certainly not necessary but when it comes to creating 'relatable characters' or relatable stories, romance is almost guaranteed to be involved. Coming of age, heartbreak, tragedy, happiness; love will always be involved. For relatability, I feel like there should always be some form of romance involved, even if insignificant to the story as a whole. I won't lie, I like romance involved. My own comic should be hint enough of that. As a main plot, it's at the bottom of my list of interests. But as a driver for a character or a main plot? It has a very important place.
Of course it isn't necessary as you say. But you can tell what people like by just perusing the comics on this site, yes?
Now how to make a GOOD romantic subplot (or main plot) is another story.