They have an incredible team but their browser is a skin for chromium compared to what it was before they dropped their engine (shortly after the founder left due to a board "too quarterly oriented".
A couple years later the new opera is till far beyond what it was and it seems they're not even trying to fix this while vivaldi on the other hand is driven by a vision and has made much more progress in a more timely manner.
I've been using opera as my main browser since they removed ads in 2005, today I'm still using presto based opera with no plan to switch to the blink based version of opera because many of the features that made opera are missing and are not coming back which make the "chromium skin" designation a reality.