@jkels They are very different when using drag & drop, as I explained. Again, in other browsers I'm able to grab a tab, and drop it into the bookmark bar or any folder on the bar, without requiring any additional user input. That's not possible in Opera - when you do that, it always prompts the user to rename the new bookmark, which is completely unnecessary and annoying, because I very rarely need to rename my newly created bookmarks. So there should be an on/off toggle in the settings, or just disable the prompt.
And the methods you suggested with Ctrl+D or bookmark button require even more user inputs and navigating sub-menus so I never use those. This is about using mouse only, and putting the bookmark exactly where I want via dragging, without extra obstacles.