IIRC Vimium was the one that was pure hotkeys, no commands. Waaay back when Vimperator died with Firefox Quantum, I tried a bunch of different addons that still worked and Vimium was probably the least powerful of them.
Currently I use Vim Vixen[0]. It's still nowhere near as feature-full as Vimperator was, but nothing can be nowadays. My only real complaint about it is how link hints don't let you complete with the link text like Vimperator could - it's the one thing that as far as I can tell, no replacement supports even though it's a whole lot better.
Tridactyl does let filter links like that with `:set hintfiltermode vimperator` and `:set hintchars 1234567890`.
Vim Vixen unfortunately has been unmaintained since May [1]. If anyone knows ueokande personally, could they let him know that I would be happy to help get some releases out? I sent an email yesterday but I am not optimistic as it seems like quite a few people have tried over the last few months.
I use Qutebrowser and it's fantastic, I even wrote some userscripts for it which are probably easier to build than web extensions.