Off the top of my head the purposes I've seen for them: - building native bindings (node-sass) - asking for funding (core-js)

... Probably a few more but the native case is probably the biggest and the packages I'm using nowadays ship precompiled blobs in optionalDependencies. Install scripts seem to be out of favor.

After the backlash of using postinstall scripts for funding requests, most of that moved to the dedicated infrastructure of the `"funding"` key in package.json [1] and the `npm fund` [2] command. (Not that most companies/users pay any more attention to this funding request messaging other than maybe adding `--no-fund` to some of their `npm install` scripts, but it is still an improvement over using scripts to do it.)

[1] https://docs.npmjs.com/cli/v10/configuring-npm/package-json?...

[2] https://docs.npmjs.com/cli/v11/commands/npm-fund