WebKitGTK (despite the GTK name?) seems to be the most optimal way forward for a future desktop Linux web browser. My position is still that the KDE and GNOME teams need to have a serious conversation about picking an engine together, optimising it for Linux/Wayland use, and build it in such a way that both KDE and GNOME can build their own UI on top.
This project should've started at least five years ago, but the next best time to start is today.