I don't feel like I have strong input on Tapas as a user since I really approach it as a creator. The app and desktop design has been changing a lot recently to balance community comics with premium content better, and I like what I've seen but it's still in progress and I haven't used it much.
As a creator, though, I think ink and ad sense is way more accessible than the ad program on webtoons. We also have the ability to schedule, and users can see when a future episode is scheduled for, which is nice. One of the best things about Tapas is their mature content policies, which while still limited are more reasonable than almost everywhere else. Especially since you can mark specific pages as mature rather than the entire comic, which is helpful to sensitive readers that might enjoy a mature comic but want to be warned if certain kinds of content it skip it.
we also have the gif support that allows for animated comics, so that's another bonus for Tapas that I know webtoons lacks. However that's probably not a Tapas only thing.
I think our ability to find comics on Tapas still needs improvement, but I'm happy enough here to give Tapas the time to figure it out. But that would logically be an issue of comparison based on your criteria.