Feels like a comic-by-comic basis xD we've had this convo on twitter before, but the comic that I started uploading at the start of October to both tapas and webtoons has 4x more views and 3x more subscribers on Tapas than webtoons.
Granted I feel like a lot of my traffic on tapas is simply due to being involved in this community xD roughly 2/3 of my subs here are folks I talk with a lot and/or read their work as well, so I guess if you took them away my sub count would be about the same on both platforms (although I have no clue who my subs on webtoons are since we can't see them haha).
But yeah, it certainly doesn't seem that Webtoons universally performs better for every comic. Even so I'm happy to use both platforms and extend my audience on both to the best of my ability ^^