SCOTUS agrees with you.
https://www.jordanucmjlaw.com/blog/2015 ... iolated-f/
"An officer...may conduct certain unrelated checks during an otherwise lawful traffic stop," ruled Justice Ginsberg. "A dog sniff, unlike the routine measures just mentioned, is not an ordinary incident of a traffic stop." Her majority opinion also stated: "A police stop exceeding the time needed to handle the matter for which the stop was made violates the Constitution’s shield against unreasonable seizures."