But coming from a person who read (some of ) the webtoon (not the novel) the changes made are absolutely unnecessary. As other people said, the romance is forced—that is because it is added unnecessary plot line—the webtoon had no FL (at least at for most of the story, if not all)

The show has its funny moments, but the romance plot line was not a decision that should have gone through. Maybe it was for the sake of making it a TV series to have more plot that is easier to wrap up, but the charm of ML has been lowered as of such. The story should be of ML mainly, not a budding romance.
The choice of FL was also a bit uncomfortable, as it felt like a sasaeng fan (as another review stated)

Other changes I would like to nitpick are just minor changes due to it being liveaction and not a webtoon, however in my heart I am just a little sad about it.