Privacy of WebKit Engine

I have learned that Firefox’s Gecko engine has vulnerabilities in sandboxing and site isolation, making it less secure compared to the Chromium engine.

I am curious about the security of other browser engines, such as WebKit. Even though it comes from Apple, it is an open-source engine. How are open-source browsers using this engine, like Orion, in terms of security?

Orion isn’t open source. Gnome Web is an example of an open source Webkit browser.