I really do prefer page both as a reader and a creator, but Tapas and Webtoon users seem to prefer scroll. Honestly, this does depend a lot on what technology we are using, and people are using phones...for now. I do feel like more and more kids have tablets, and that number is only going to increase. But, for now at least, scroll is king on Tapas and Webtoon, and they very much encourage vertical storytelling, so if you do a page format, you'll have a harder time growing an audience.
But, stepping away from whatever tech is currently in vogue, when it comes to storytelling, it is two completely different feelings of a format. Scroll does so good for vertical landscapes and almost poetic dialogue moments where you can scroll down to each passage of dialogue offset by floating, dreamlike pictures...If you have a lot of emotional talking, especially for slice of life, or romance, vertical comics can take away some of the tedium you can get from talking head-portions of your comic. You can get real abstract with it.
But, you do get tired of seeing long vistas over and over again since there isn't as much variation you can do with panel width. Scroll also takes away the ability to move your eye around the page as well as page format did, so action comics just aren't as...active. There's a few comics I think do a good job with scroll and action but they have to REALLY push that action to get it moving, and often they have to zoom into a panel, and then post the same panel again far away because the vertical format forced them to crop the entire scene. This also means you also can't do as many scenes with lots of detailed characters at a distance or your people will look like ants.
Like my favorite scroll comic I'm reading right now as far as action goes is Midnight Furies.
They really made it feel like the same amount of action you would get from a page-format and that's really hard to do.
And on top of that, since there isn't as much variety in the size of the panels you can use, most of the feeling of time passing in a scroll comic is done mostly through...scrolling. Some people love this, some people hate it. If I see another 6 billion pixel long gradient transition, I might die.
But my final thought is I think a lot depends on the style of comic that you're doing. Mine, for instance, is a very simplified style, and so it really suffers if I zoom in all of the time. The characters were meant to be seen rather small, like a newspaper-strip. When I did it in page format--it didn't look great, and felt very anemic. Scroll format desires a much greater level of detail to be passable than page format, so you'll be automatically doing a lot more work.
But most of the reason I prefer page format is because there's a lot more design. The way that panels are laid out on a page, the way contrast moves your eye around--artists often have to get really, really clever, and seeing the fun ways they break expectations is part of the fun of reading them.