The terminology of "static" and "dynamic" may not be helpful any more, but there is still an important architectural distinction between the user executing the

The terminology of "static" and "dynamic" may not be helpful any more, but there is still an important architectural distinction between the user executing the website code in their browser (in the case of a Single Page Application), and code being run by another computer on every page fetch (or at least every cache miss). From a security perspective this distinction matters, because if there's no code runtime/interpreter on the webserver, then the runtime/interpreter can't get hacked by a malicious request (or a flood of requests), while shipping all your frontend source code to the user might have security implications too. This decision also impacts costs and latency.