Funny seeing this here, I just switched to Vivaldi yesterday because of this.
I really wanted to use mouse gestures and Vim-like controls again, and the WebExtension version of those addons is not nearly reliable enough.
The problem seems to be that those control extensions can only work by injecting Javascript into webpages, which (1) takes a moment to work when the page is loading, and (2) doesn't work in New Tab page. The effect is that even basic shortcuts like "next tab" fail to work often enough that I'm willing to switch browsers.
I really wanted to use mouse gestures and Vim-like controls again, and the WebExtension version of those addons is not nearly reliable enough.
The problem seems to be that those control extensions can only work by injecting Javascript into webpages, which (1) takes a moment to work when the page is loading, and (2) doesn't work in New Tab page. The effect is that even basic shortcuts like "next tab" fail to work often enough that I'm willing to switch browsers.