Then why stop using it?

The only website keybinding that really frustrates me is /, which many sites bind to their search feature. I don't understand why they do that. Don't web browsers already have page navigation features? Either the user is a mouse maid and can click the search field themselves, or they have a keyboard navigation tool such as Tridactyl and the binding just overrides the tool.

I think page-specific keyboard-driven navigation has advantages. For example, in Gmail j/k navigates between email threads. I can't see that Tridactyl provides this functionality.

For the search functionality specifically, I guess it's possible to find a solution. The page-specific search shortcut will just focus a specific element on the page, and maybe that could be provided on a different shortcut in addition to /.

You can use unbindurl, so you can unbind tridactyl's j/k on mail.google.com, for example. Keys not bound in tridactyl are passed through to the page.

Because once it's disabled on some sites, I get annoyed by the inconsistent interface.

If it's just one or two binds that are causing issues on a site you can unbind them with `:unbindurl`.

Have you tried qutebrowser? Also I suggest you to give tridactyl another try, it vastly improved, especially the hint mode, plus you don't really have to disable the extension if it gets in your way, just switch to "ignore mode" and voilà