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 advertis...
Tried using Vivaldi at one point and I really liked it but it was noticeably slower than both Firefox and chrome even though it's just another chromium fork. I've since switched back to Firefox and haven't looked back.
Actually after Opera switched engine from Presto to Blink and become another Chromium-based browser I was a bit lost, and switched between different browsers while never really had that "good connection" I had with Opera, but I eventually switched to Firefox and I don't really see any other alternative right now. It just works, and supports free and open web.