For your site. If you don't serve ads that rely on Google-FLoC rankings, then yo...

For your site. If you don't serve ads that rely on Google-FLoC rankings, then you won't see any impact. Otherwise you'd see a financial hit.

If your users go to another site, and they don't have client-side FLoC-blocking in Chrome, your settings obviously won't do anything for them.

So it's a nice step for your users, but is limited.