Opera has been using WebKit as their core engine for the past couple of years.
And I do use Opera as a default browser.
The correct Ctrl+Tab behaviour which works like Alt+Tab (switch between the most recent tabs, with a small popup list of tabs) is the main reason for that. Much more productive for me than the usual "cycle over all of open tabs sequentially" behaviour that Chrome, Firefox, and everyone else have (except the Vivaldi browser).
[1]: https://addons.mozilla.org/en-US/firefox/addon/tab-mix-plus/
1. Go to about:config
2. Search for browser.ctrlTab.previews
3. Change value to `true`
4. Close tab
Now your ctrl+tab should work as you want.
If you wanted multiple sites open you had multiple browser windows on the taskbar.
That became unmanageable quite fast, so we got tabs.
Note btw that even the earliest Opera had "tabs". It used MDI to provide multiple sites within a single browser window. This stuck with Opera all the way to version 12. After that they changed over to being a Chrome clone.