Opera used to be a fantastic web browser, with a custom high-performance Presto rendering engine and features like tabbed windows that didn't show up in competing browsers until years later. However, the modern Opera browser is a shadow of its former self, reliant on chasing trends and meme advertising to
I’ve never tried it, why is it preferable over the default horizontal tabs?
I wouldn’t say preferable but it’s definitely very useful. When you have about 45+ tabs open(Yeah I do that) and the vertical tabs are too squished to show their titles, you have to then manually swap between tabs by either clicking or ctrl+tab etc to search for a specific tab.
Vertical tabs are like sidebar links in explorer except better, you can search tabs by address or title, drag and drop them for organizing, pin them to the top etc.