1Password install size

It's because rather than being a "native" application, 1Password is using the Electron framework which automatically adds 250 - 300MB to each application because it bundles Chromium (the open-source browser engine and node.js) inside every application. There's also the ~140MB "index.node" add-on (binary module) which enables node.js to call functions written in other languages.

Lots of cross-platform applications use Electron because it is easier for the developers, even though it results in a worse experience for users due to bloated application sizes and non-native look, feel and functionality compared to native apps.