Webtoon, though not inferior in terms of a platform for storytelling, just doesn't offer as much potential as traditional panelling in manga does. Though it can present action, pacing and sometimes even pull off Junji Ito level of suspense with its use of simply scrolling down to a revealing page, after seeing through the obvious privileges, everything else seems like a discount in comparison. Not much freedom in terms of art and a streamlined way of reading meant clever panelling is restricted to verticality, instead of beautiful two-page spreads you'll usually see in manga.
But really, it all depends what kind of a comic you're going for. I always felt like Chainsaw Man would fit a webtoon like a glove, while the story-focused Berserk or One Piece should probably stay in manga format for the better.