The current model of most webcomics/webtoons is vertical scroll. That's not to say you have to change your comics to fit this model, but it is something you can experiment with to see how your own work is best represented with that medium.
Honestly, it was said best in this previous post:
It's all about being willing to learn how to work with vertical/traditional scrolls and how you can find benefits in both towards your story. I do a mixture of both for my comics, leaning more towards vertical scroll, and I personally say that both have helped me improve my comic. So I say it's good to try and use both here and there.
It's not about which is better, per se. It's about which one properly helps execute your comic (with practice), and how much you experiment with them.