"What I want is very simple: I want software that doesn't send anything to the Internet without some explicit intent first."

It exists. I use such software everyday. For example, I am submitting this comment using a text-only browser that does not auto-load resources.

But this type of smaller, simpler software is not popular.

For example, everyone else in this thread is likely using a browser that auto-loads resources to submit their comments.

Even though HN is more or less a text-only website and this "feature" is not necessary for submitting comments.

All so-called "modern" web browsers send requests to the internet without explicit intent first. Via auto-loading resources and via Javascript, e.g., XHR.

Brand new Apple computers send packets to the internet as soon as the owner plugs them in for the first time. This may enable tracking and/or data collection. Apple proponents would likely argue "convenience" is the goal. This might be true. Nevertheless some owners might prefer that the computer should not automatically send packets to remote Apple servers. Often it is not even possible to disable this behaviour. Computer purchasers never asked for these "convenenience" features. Like the subject of this submission, Apple Photos, these are Apple's decisions. The computer owner is not allowed to make decisions about whether to enable or disable "convenience" features.

As the court wrote in its opinion in US v Google, default settings are significant. In this case, it is more than a default setting. It is something the owner cannot change.