It really depends on your needs. Both platforms have their own pros and cons, depending on what you need:
Tapas:
-As a creator, I have better success here than in Webtoon. Which is surprising because I'm told Webtoon has a bigger audience. Most likely because my comic fit in the popular genres of Tapas (Romance and Fantasy). Also because my art style is anime-like, which Tapas prefers. If yours doesn't have that, tough luck.
-Encourages community with both creators and readers. Really helpful especially when you're starting out.
-Has better creator support. I wouldn't have that many subscribers if I wasn't alerted of subscriptions, comments and likes to build a following on. Has lower requirements to get paid. Easier to manage your work here too.
-The UI is cute but as a reader, I hate that you get railroaded to read the popular and favored works. It's also harder to navigate and discover works on your own.
-They promote more studio made comics. In all my time as a reader, I've never seen any non-studio comic get involved in their ink promotional activities like being featured in new releases where you need to read at least three chapters to get ink. I don't read much here because their recommendations are bland. It's always the same tired isekai with overpowered mc or rewritten villains/villainesses and fantasy comics with uninspired and overused East Asian/European dressing.
Webtoon:
-it's the Wild Wild West out here, both as creator and reader. As a reader, you'd probably awed at all that opportunity for adventure. There's lots of diverse works to discover out there, in terms of topic and art styles (not limited to anime only) and Webtoon lets you do that more easily. And it's more supportive to you in terms of searching for comics, keeping track of what you read and alerting you. Also, you can enjoy their originals with some patience unlike Tapas where they hit you immediately with a paywall (but Tapas gives you a lot of ways to get ink to pay for that whereas Webtoon is too miserly with giving you coins and nickels and dimes you so I guess they're even?). As a creator tho, it's as bare as a frontier. Very few supports at all; you gotta build your own tools. No community present to build your following; you gotta build your own. Their discord is just like a corporate bulletin (their twitter and insta are fine tho). It won't alert you on what your readers are doing; you have to find out yourself whether anyone commented, liked, or viewed your work. Their user analytics is bad; it doesn't tell me anything useful. I haven't been around long as a creator, but I've read a lot of creator gripes regarding Webtoon than Tapas. Lots of contract shenanigans, where original creators are regularly dungeoned for not hitting improbable metrics like half a million subscribers on launch, and very high requirements to get paid.