firefox sadly is still what you should use.
For all of the (valid) criticism against FF, it's still the best available browser that's not just an experiment IMHO.
Edit to add: part of the switch back is that FF now supports, to some degree, all the features I was using Zen for: vertical tabs (needs customization but works well enough), custom search "engines" (ie, shortcuts), split view, not-Chrome
I don't want to burn out my battery quicker than usual, so I was forced to switch off. I'm currently trying Orion instead and have been loving it - aside from several poorly implemented websites just not working on it. And the Cloudflare false positives, but that's as much or more an issue on Zen.
I don't use macOS anymore, but when I did I used Firefox without missing out on anything Safari would have given me. Now that I've abandoned macOS I don't think I can name one advantage of installing a WebKit browser on my system versus something Chromium-based.