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
For gecko the best alternative to old opera and Vivaldi I found so far is floorp
I looked it up and it looks great. Currently downloading it to give it a try. I wonder how it compares to LibreWolf though.