It's not really a question of which one is "better" in absolute terms, because it depends a lot on what you specifically need. But it's true that Clip Studio Paint has tools designed specifically for manga and webtoons, while Krita is more versatile but less specialized in that area. Clip has ready-made screentone materials, more robust perspective tools, and the manga community there is huge, which means more tutorials and resources. Plus, it has native support for panels and speech bubbles that makes page work way easier.
That said, if you're already comfortable with Krita and it works for you, switching might not be worth it just for the sake of it. Krita has improved its drawing tools quite a bit and now has good brush options. The question is: what do you feel is missing from Krita right now? Is it speed? Very specific features? Because if it's just the "there must be something better" syndrome, you might be wasting money for nothing.
If you're seriously considering switching, the sensible way is to test Clip Studio Paint during the trial period. See if those extra tools actually make a difference in your workflow. And remember that Krita is free and open-source, while Clip is a subscription, so there's an ongoing cost involved. Is it worth it for you?