Edit: Looks like you can opt-out of that "new look and feel" pretty easily under the appearance settings but still, whats with putting rounded corners everywhere?
Edit 2: "Explore the web with a softer, more friendly aesthetic featuring rounded corners […] Designed to complement your operating system, whether on Windows 11, MacOS, or Linux." The fuck does that mean? Windows 11 fair enough but most Linux distros don't look like that at all.
It is possible to remove it, needs a bit of work and running scripts as admin to do it but you can figure out if you look it up. I can’t remember how I did it and I don’t use windows anymore but first page results should bring it up.