The only part missing, is Firefox slightly slower startup time (although that improved as well).
Then once WebRender lands, well, who knows? I assume Google are planning something in response - the continued dominance of Chrome is worth considerable $billions to them...
TabGroups was really unique in that it felt (to me) like the kind of interaction-redefining change that tabbed browsing was in the first place. I'm adjusting myself to using virtual desktops and KDEs WM-level tabs to compensate, but I still miss the addon.
I’m surprised the built in containers left behind the extensions option to always a url open in a specific container. To me that’s the unique interesting bit — my banks can always be in my banking container, Facebook in a social, etc. By having the browser force the mapping I can make sure that I minimize cross-contamination, reducing attack surface area and increasing privacy.