I made an account only and primarily to express that I also really don't like the new look. It broke some functions that opera used to have zero issues. Aesthetically it is not my jam either, it used to feel clean and sleek and now it feels bubbly and almost noisy because of it.
Everything everyone said in this thread is correct. I didn't even update it on purpose because I'd seen how it looked updated and decided I didn't like it, but it updated on its own and it's just a massive disappointment and frustration.
At the very least, I just want the option to return to the old browser layout. I really enjoyed what Opera brought to the table before this update and made it my primary browser because of it. I'm fully prepared to drop it if this is the new normal.