It looks like the company has left the option to use the compact mode introduced in the new Safari at WWDC in June, but users now also have the option to use Safari's more traditional tabs view.
John Gruber of Daring Fireball noted that Apple has restored tabs to Safari as they are now available to macOS Big Sur users for those who haven't yet upgraded to Safari 15:
An updated page for macOS 12 Monterey (release next Monday) shows that Safari 15 is back to real tabs instead of "tabs." Compact mode is still an option, which is great - it's how this design should have been approached from the beginning. Safari 15 on iPadOS 15.1 is also keeping up with the times.
Safari 15 on all platforms has one single design bug left: the tab close buttons are on the right instead of the left on the iPhone. Pretty good result considering what was shown back at WWDC.
The new Safari has been a major problem for many users who have been testing and running the latest generation of the browser. Apple received a lot of censure for the radical redesign, which many felt was less user-friendly than the previous version of the company's default browser.
macOS Monterey itself will be the default operating system for the new generation of MacBook Pro laptopsunveiled this week.
Source: daringfireball, imore