Maybe? But I believe that a good author can make the romance feel meaningful even if it’s only a subplot. Instead of creating a story where the FL actually has to plot and struggle to go up against her supposedly cunning enemies, the author used the ML (who, again, has no personality) and the sudden stupidity of the villainess to make the FL look more desirable, intelligent, and give her an easy source of power. If a good romance subplot alone is enough to overshadow the MC then maybe she’s not a well-written, memorable character to begin with.

This story was a rollercoaster, and I don’t mean an emotional one. Just the plot itself was wild.
SPOILER!!!
The story was mostly great. Clearly, the author is good at storytelling, planting seeds of foreshadowing to neatly tie them up at the end. But especially towards the end it got a bit ridiculous; the way she was dragging out the sister’s death for 20 chapters felt like plot filler, the whole time travel thing, etc. Toward the end I couldn’t take it seriously anymore and then the author flashbanged us with that panel of “God” and I nearly fell off my bed from laughing.
Unfortunately, the author isn’t nearly as good at writing romance as they are at plotting. The romance was bland, and like others commented, the ML existed only for the purpose of simping and supporting the FL without any semblance of individuality. Honestly, there’s more tension in Lohan and (reincarnated) Lady Iris’ relationship and I’d be more interested reading about them than the main couple. The same goes for the Mielle and Lady Iris, who were dumb-ified at some point so the FL could defeat them.