That sounds like it was a bug / mistake than a deliberate decision by the company unless I misunderstood something?

Information about every executable your run on "your" laptop goes to a special server belonging to Apple. It must be a huge and costly mistake...

But it is.

No it isn’t. Most apple users rely on apple to protect them from threats.

The best security you can get is in prison. I wonder why people don't want to go there. /s

You can implement malware check in many ways. This one is the worst; it also introduces a huge attack surface.