Dashboards can easily take two or three tabs.
The bug tracker is opened on a tab as well as the ticket page. You have a pull request opened to review it, and you check something in the repository. Pop open a couple of diffs to check where someone messed up in the past.
And in the meantime you have Spotify/YouTube.
A dozen tabs easily.
Factor in task switching, checking CICD pipelines, and of course HackerNews opened somewhere, and you can get multiples of that.