Why is changeOrigin: true required when target is https?

[ChristopherZhong]

Based on documentation changeOrigin is needed for name-based virtual hosted sites, so I'm confused as to why it is required when the target is to a https site? There is another related discussion #557 but it does not provide the answer to the question that I'm asking.

Take the following example, which is a proxy to 'https://google.com'.

const app = express();

app.use(
  '',
  createProxyMiddleware({
    target: 'https://google.com',
  }),
);
app.listen(3000);

This results in the following error.

[HPM] Error occurred while proxying request localhost:3000/ to https://google.com/ [ERR_TLS_CERT_ALTNAME_INVALID] (https://nodejs.org/api/errors.html#errors_common_system_errors)

However, after adding changeOrigin: true (as shown below), it works as expected.

  createProxyMiddleware({
    target: 'https://google.com',
    changeOrigin: true,
  }),