Torres v. Madrid (5-3)

Carpenter v. United States (5-4)

Collins v. Virginia (8-1)

Barnes v. Felix (9-0)

These are all Supreme Court cases that were specifically about the 4th amendment and happened in the last 10 years.

The 4th amendment is over 200 years old and yet requires constant supervision by the Supreme Court to define the word reasonable or to police the lower courts understanding of precedent.

So you are wrong, with whatever presumption you are making that the word "unreasonable" is well defined.