I haven’t used Opera in a long time, but I used it heavily 20 years ago. Back then you had to pay for it or there was a big ad banner on the toolbar.
It certainly wasn’t always Chromium based, Chrome didn’t come along until 2009 or something. Not sure when that change happened.
If I had to go back to that job I was doing (Internet Help desk) again, I’d consider Opera again. It was fast at navigating an intranet site where all the images were cached locally, but the killer feature for me was the back/forward. If you went back, all the stuff you typed in the form was still there. So you could resubmit it if the session had timed out or there was an issue.
I still use mouse gestures (an Opera thing) via extensions with whatever browser I have used since.