Blink supports Windows, Android and Linux better than WebKit or Gecko does, to name at least one one reason. If it weren't for uBlock I'd probably be using a Chrome fork right now.
Wipr and UserScripts on Safari prove to me that that's not a real issue...I understand compatibility problems are still issues, but ads/etc. are a fully solved one for Safari users.
For me it’s a lot of layout and rendering bugs that I run into with somewhat normal CSS transforms.
Anytime I build a site that has any kind of animation, there’s at least one weird rendering bug on iOS.
Also that stupid playsInline prop that if you forget it makes any video in the viewport hijack the browser and go fullscreen.
WebKit is not lacking in things your average dev needs and it’s not that big of a deal to work around, much like it’s not that big a deal to work around things in Gecko - or presumably Ladybird whenever it becomes usable enough.