> it is very hard to craft a set of permissions to allow that package to retry requests to certain addresses you'd like to retry without also letting it throw random system metrics it's collecting to an ad-server

If you're expecting to have to craft ACLs program-wide for that package, then sure, that's going to be hard. That's more coarse-grained than what I'm talking about here though.

Imagine, if you will, a programming environment where modules you load don't have any authority to access the network, filesystem, etc unless you pass them in. They're just not in scope. In such a language, the default way to grant HTTP access might look like this in pseudo-Python:

  http = require("http")
  myMaliciousLibrary = require("myMaliciousLibrary", http=http)

Now, this library has the problem you mentioned; it can make arbitrary outgoing HTTP requests, meaning it can send any metrics it collects to an ad server. It can't access the filesystem because the filesystem isn't in scope either, so what it can collect is limited, but still more access than it needs. So here's one way you might fix that (obviously highly simplified/incomplete in its implementation):

  class ProxyHTTP(origin="https://example.com", http):
      def __init__(origin="https://example.com"):
          self.allowed_origin = origin
  
      def get(origin, path="/"):
          return http.get(self.allowed_origin, path)
  
  http = require("http")
  myMaliciousLibrary = require("myMaliciousLibrary", http=ProxyHTTP(origin="https://good-site.example.com", http))

Now, this version of myMaliciousLibrary gets an object that looks like the http library it would normally use; it just happens to ignore the origin parameter that the library passes to it and uses the one it was initialized with instead. Now, that library can make requests to good-site.example.com, but if it tries to make a request to adserver.evil.com, it'll go to good-site.example.com instead. (You might also imagine a version of ProxyHTTP that just throws an error if the request's origin isn't the same one it was initialized with, or isn't in a list it was initialized with.)

Most of today's programming languages aren't strict enough to enable this of course; JavaScript isn't there yet for example, and most other languages aren't even close to being able to do this. But that's mostly because they don't provide strict enough encapsulation, not because they're lacking some complex security enforcement mechanism.

> I think it's just because most of us accept the risk, it's highly unlikely that malicious supply chain attacks will suddenly sink our businesses so we accept a reasonable level of security in exchange for what feels like a modest risk

I just think people are accepting way more risk than they realize, given the number of dependencies in modern applications and the amount of access each of those dependencies have. It feels crazy that any one of those dependencies in any application could exfiltrate massive amounts of sensitive data from any machine it happens to run on.

On Windows I can just

   choco install vlc

> The whole point of the earlier comments is that it is preferable to use a package manager instead of using a browser to download binaries.

But there are package managers for Windows, aren't there?

Microsoft even has its own app store, that you need to use to install applications such as Windows Terminal.

People often install software on Linux and macOS by downloading installers using a browser. In fact, that's how non-bleeding edge versions of Xcode are installed.