Vivaldi allows placing the tab bar vertically[1], I've used this since Opera times (an Opera founder departed the company after its Chinese takeover, and started Vivaldi), I currently have around 120 tabs open in 5 windows (actually you can also scroll on the tab bar itself), yeah too damn many.
I suppose people without AppleScript can write a browser extension that iterates through all the tabs and report the count to a Grafana. It would also be interesting to also record ages of tabs (e.g. time since it was opened/time since it was last seen)...