Ladybird is a pet project of no relevance to the web. there is no tech advantage, its just as riddled with vulnerabilities. chromium and webkit are the winners. you need a whole new ecosystem to get something different.
I think Ladybird is becoming more than that. It's actually helping set the web standard specifications straight in many cases and a from-scratch implementation will have its own advantages once it catches up. Which it will. There's no permanent winner as long as the standards are open.
Ladybird is playing catch-up with features already done years ago. They can either break compatability, or follow. Theyre following, which makes them yet another dead end.