A couple that I can think of that are more epic in scale where romance is present but isnt the main plot:
The Book of the Ancestor Series by Mark Lawrence. This is warrior nuns with a slowburn f/f romance. Its certainly a subplot but it is not ignored in any way.
The Nightrunner Series by Lynn Flewelling this one has great characters and relationships (friendships and romance.) The main romance is m/m and its more of a consistent throughline, especially later in the series. You really get to hangout with them while they are together but facing other problems. That being said these books take a weird turn in book 4 and 5 (7 books total). u/alicethegamedev wrote a more comprehensive review pretty recently that gets into some of whats weird about book 4 and 5. I am glad that I read them, but if you got that far loved the series but and didnt vibe with book 4/5 you could skim or read summaries of them and then jump back in at 6 and really not miss much. They are more episodic than epic adventures than one large epic story.
Kushiels Legacy by Jacqueline Carey this one is interesting because its a super epic, adventure laden plot, but often gets filed away in romance or erotica because the main character is a sex worker/spy and the sex scenes are pretty graphic. That being said I think its a major disservice to do that because the plot, the political intrigue, the adventure are what really make this series great, especially the first three books. (Its three trilogies in the same world, but each trilogy has a different main character and happens at different points in time.) The mc of book one is a woman and she has clients who are men and clients who are women but her actual romance is more slow burn and is m/f. The romance is certainly not the main plot. Content warning: these books do contain rape but it is not romanticized.
The Twelfth House Series By Sharon Shinn this one walks the line of what you asked for because there is an overarching epic plot, but the series focuses on a group of friends who are really rocking a chosen family vibe and each of the books (there are four and then a spinoff that a bit different) focus on the romance of one of the members of the chosen family while they deal with the epic happenings around them. They are very romance style with HEA's for each of the characters. Book 2 is the weakest imo and I thought it was worth pulling through for book 3 and 4.
Empire of Sand by Tasha Suri really fits into the catagory of fantasy- romance, but it has a very epic plot along the way. I would say the rest of the plot is just as important as the romance in this one. It has a really cool dance/movement based magic and is set in a south east asia/india inspired fantasy setting which I found very magical. Content warning: this book has some dubious consent because the main characters are forced into a relationship and while they do fall in love they are forced to have sex by a bad outside force for reasons
Some other people have recommended books by Grace Draven and I specifically love Radiance but it really is a little but more like a capital "R" romance-fantasy, which it doesnt seem like you necessarily want, especially in book one, which is pretty slice of life vibes but book two does start to become more about an epic plot and book 3 comes out on September 15. I do love this series but it might be more romance focused than what it seems like you described wanting.