The Bitwarden product design team has unfortunately latched on to “modern” design fads, which impose gratuitous margins and padding (and rounded corners), and it has repeatedly introduced “refreshed” UI designs that reduce information density in the browser extension viewport (e.g., in 2022 and 2024).
I posted a comparative analysis of the evolution of the Vault view design here: Browser Extension Redesign beta - #48 by grb.
There are a few Feature Requests in response to the current state of the UI, but they have not received much attention:
Firefox users can customize the CSS, but this work-around is not available for other browsers.