It's awesome tool which should be used in every company doing JS/TS to speed up development, and remove need to care much about code style - which will be great by automated format.
Everyone on the team can be on the same page about style and focus more on good quality engineering instead of styling nitpicks. Prettier works, is fast, and is extensible. It also supports other languages and file types such as TypeScript, .graphql files, CSS, and more.
I'm not a Javascript developer so I love that Prettier makes generally good formatting decisions for me, freeing need up to think about the code. It's easy to apply Prettier to any project I'm working on, even if other proper in the project aren't using it.