This is an unfortunate thing about a whole lot of legal precedent in the US.

Courts made a pretty reasonable set of tradeoffs around the 4th amendment for search warrant vs. subpoena, police officers observing you, etc.

During the 19th century.

Unfortunately, modern data processing completely undermines a lot of the rationale about how reasonable and intrusive various things are. Before, cops couldn't follow and surveil everyone; blanket subpoenas to get millions of peoples' information weren't possible because the information wasn't concentrated in one entity's hands and compliance would have been impossible; etc.

Exactly. Constantly monitoring and aggregating your movements everywhere is basically stalking.