Maybe give them a second? Yes, it's usable for applications web views if you're willing to restrict yourself but for general purpose web browsing there's still a lot that needs doing (but work is progressing). Under Google's management, web tech has grown fast. And it's an ever shifting living standard. There is a lot for any alternative browser engine to implement, let alone keep pace with the changes.
Servo is 14 years old, it's hardly a new project. Ladybird has come much farther in a shorter amount of time. The issue has always been Mozilla not being focused.