I can’t speak to whatever konqueror uses these days but webkitgtk is notoriously behind and difficult to work with. You can read posts from the Tauri devs questioning their entire approach on Linux due to it.

I really hope Kagi contributes back upstream to improve the situation, it’s needed.

Edit: looks like konqueror uses qt web engine which is chromium. The irony of the KDE browser abandoning WebKit while the GNOME browser still tries to use it is too much.