From my perspective, Webtoons appears to be very heavily slanted towards longform romance and drama in a manga style, whereas Tapas has always appeared to focus more on bite-sized comics and anime styles. Of course there will always be many examples to the contrary on both sites, but yeah, there does seem to be two distinct crowds, even though there's some overlap.
As for me, it's taken years but I've finally come to terms with the fact that my story probably won't ever have the kind of stratospheric response I've witnessed others receive on both sites purely because it doesn't neatly fall in to the popular story types, and I'm not all that willing to pander to the crowd and just chuck in some trope because it's the flavour of the month. But that's cool, there's still a slice of the crowd on both sites it's appealing to. Webtoons is winning for me at the moment, but Tapas is making a late comeback, and could feasibly catch up in the future, despite the 7:1 disadvantage.