@zalex108 Other user's and myself are encountering this problem, but it's not really the GPU either.
It's the in-browser audio playback for everyone, and some are finding it's also the animated icons on the tabs, for anything, anywhere.
It seems to be with any browser based off Chrome/Chromium, which Opera is based off.
Boot up youtube then -mute- it and you can see a dramatic cut in CPU & GPU usage.
It's been getting worse, and people have been reporting the problem for months, and it's tied into the 'tab icon is constantly loading' issue somehow.
Who thought it was a good idea to remove the stop-loading page function from a browser?
On my side:
Mute is unnecessary, just hover the tab to change to a static audio icon.
Vivaldi works fine.