The Internet was originally designed to fail gracefully. As routes and servers fail, the Internet was designed to work without them (to a point). Sadly the proliferation of giants like Google, Amazon, and Microsoft has put most of the Internet in the hands of a few companies.

You can technically use the Internet with every Google service blocked and all AWS / Microsoft IP ranges null routed, but it’s going to be very different and most major sites simply will not work.

Manufacturers: Best I can do is planned obsolescence.

This is the philosophy that they use when building spacecraft. Most sensors and instruments on the Voyager craft have been turned off to conserve power, but they continue to function enough to still communicate with Earth.