I often feel like 99% of webcomics and anime in general are built on the tropes of their genre- especially romance, isekai fantasy, and often action (anime equivalent being shounen). The most noticeable and irritating trope to me right off the bat is how everyone in the story (who the author likes and wants us to like) is perfect and beautiful and the absolute best at whatever it is they do, so the author/readers can insert ourselves into their perfect lives and play out a power fantasy. It gets more annoying when I'm supposed to pity the character or feel any sense of stakes or urgency about their easily-solved "problems".
I tried reading My Gently Raised Beast on Webtoon out of curiosity (thinking: what makes these stories so appealing? there must be a reason why there are so many of them), and main character Blondina is a great example of this. She is inhumanly beautiful, selfless, wise, forgiving, and clever (likely has magic prophecy powers too). She's an orphan elevated to princess status who doesn't fit in because of her background, so we're supposed to pity her.
In reality, she's adored by everyone she meets, never does anything wrong in her life, and has a flawless, utterly devoted love interest who is her pet (he shapeshifts into a cute cat), bodyguard, and a magical king in one- the most powerful person in the world with no limits to what he can do. He isn't bound by the law. He's an arrogant one man army who could walk right into the neighboring kingdom and murder their royal family and they'd have to let him.
Their only enemies either become good when they realize how amazing Blondina is and join her loyal group of followers, or they remain spiteful, evil characters with no redeeming qualities who hate Blondina out of envy and want to kill her. They don't seem at all dangerous because every attempt to hurt Blondina is thwarted by flawless love interest and his godly abilities.
And... oof. Now I'm ranting. :')
I think this comic in particular though is very representative of all the worst tropes that plague Webtoon and Tapas, and if I could attribute them to anything, it'd be the creator's desire to create an entirely self-indulgent fantasy scenario at the cost of the believability and realism of their characters/plot. Bad motivations to create a story = bad characters, bad stories.
Regardless, I think any trope can work well, as there's a reason why they became tropes in the first place; something about each one was initially compelling enough that it inspired widespread imitation. Whether it's good for a story or not just boils down to how and why it's being used.
Personally, I wouldn't mind more underdog heroes, battle couples, childhood-friend love stories, and cross-country adventures to find the Thing. Can't say whether they're 'underused', but I have a soft spot for these. ^^