Yes, it’s Blink without the bits that Google doesn’t share (I wanted to be precise that nobody can compile actual Chrome from public sources, they can build Chromium which is almost but not quite the same)

Because it works everywhere, because it’s so old.

The next best option, a decade old WebP, is a mixed bag. In its best-compressing mode it will lower color resolution and add fringing like a JPEG. In its lossless mode it may be bigger than GIF.

If you have an option to use a proper video format, go for it. But often sites just allow upload of GIFs. If you send a newsletter you never know how primitive (Outlook) the client will be.

Vivaldi uses the same engine as Chromium, and the company has been founded by ex Opera developers.

Plus you can make certain sites always automatically open in their designated container, even if you followed a link. You can keep sites know for spying away from your logged in identity. You can have your banking and other important sites in another container for extra defense in depth.