Why is typhoid vaccine not routinely given in the u.S.?

Minimal benefit. The available vaccines (live oral or injected polysaccharide) have a limited benefit (2-5 yrs) before they must be repeated. The most common use is for international travel in endemic areas where drinking water supplies may be suspect. Within the us ~400 cases per year are dxd & spread is relatively easy to prevent by maintaining proper hygienic practices.
Minimal risk. Typhoid is not a prominent illness in the us.